#Node.js 22 features

[softweb-solutions]

Discover the groundbreaking features and updates in Node.js 22, including enhanced performance, native WebSocket support, and a new V8 engine. Learn why upgrading is crucial for creating efficient, scalable web applications with expert Node.js development services.

[backenddevelopment]

Discover the latest features of Node.js 22, including updates that boost performance, security, and development efficiency. Stay ahead with the newest capabilities in Node.js 22!

[sdreatechprivatelimited]

Improve your development process with the latest Node.js 22 features!

Node.js 22 is a perfect choice for developing modern applications.

It has lots of new features, like better ESM support, real-time communication through WebSocket, smarter script execution, etc…

To learn in detail, click the link below. ⬇ https://sdreatech.com/nodejs-22-latest-features-and-updates . . .

[hindintech]

You can learn JavaScript easily, Here's all you need to get started:

1.Variables

• var

• let

• const

2.Data Types

• number

• string

• boolean

• nUll

• undefined

• symbol

3.Declaring variables

• var

• let

• const

4.Expressions

Primary expressions

• this

• Literals

• []

• {}

• function

• class

• function*

• async function

• async function*

• /ab+c/i

• 'string'

• ()

Left-hand-side expressions

• Property accessors

• ?.

• new

• new .target

• import.meta

• super

• import()

5.operators

• Arithmetic Operators: +, -, *, /, %

• Comparison Operators: ==, ===，!=,!==, <, >, <=, >=

• Logical Operators: &&, ||, !

6.Control Structures

• if

• else if

• else

• switch

• case

• default

7.Iterations/Loop

• do…..while

• for

• for...in

• for...of

• for await...of

• while

8.Functions

• Arrow Functions

• Default parameters

• Rest parameters

• arguments

• Method definitions

• getter

• setter

9.Objects and Arrays

• Object Literal: { key: value }

• Array Literal: [element1, element2, ...]

• Object Methods and Properties

• Array Methods: push(), pop(), shift(), unshift(), splice(), slice(), forEach(), map(), filter()

10.Classes and Prototypes

• Class Declaration

• Constructor Functions

• Prototypal Inheritance

• extends keyword

• super keyword

• Private class features

• Public class fields

• static

• Static initialization blocks

11.Error Handling

• try,

• catch,

• finally (exception handling)

12.Closures

• Lexical Scope

• Function Scope

• Closure Use Cases

13.Asynchronous JavaScript

• Callback Functions

• Promises

• async/await Syntax

• Fetch API

• XMLHttpRequest

14.Modules

• import and export Statements (ES6 Modules)

• CommonJS Modules (require, module.exports)

15.Event Handling

• Event Listeners

• Event Obiect

• Bubbling and Capturing

16.DOM Manipulation

• Selecting DOM Elements

• Modifying Element Properties

• Creating and Appending Elements

17.Regular Expressions

• Pattern Matching

• RegExp Methods: test(), exec(), match(), replace()

18.Browser APIs

• localStorage and sessionStorage

• navigator Obiect

• Geolocation API

• Canvas API

19.Web APIs

• setTimeout(), setlnterval()

• XMLHttpRequest

• Fetch API

• WebSockets

20. Functional Programming

• Higher-Order Functions

• map(), reduce(), filter()

• Pure Functions and Immutability

21.Promises and Asynchronous Patterns

• Promise Chaining

• Error Handling with Promises

• Async/Await

22.ES6+ Features

• Template Literals

• Destructuring Assignment

• Rest and Spread Operators

• Arrow Functions

• Classes and Inheritance

• Default Parameters

• let, const Block Scoping

23.Browser Object Model (BOM)

• window Object

• history Object

• location Obiect

• navigator Object

24.Node.js Specific Concepts

• require()

• Node.js Modules (module.exports)

• File System Module (fs)

• pm (Node Package Manager)

25.Testing Frameworks

• Jasmine

• Mocha

• Jest

[npmjs]

This year in JavaScript: 2018 in review and npm’s predictions for 2019

This study is adapted from my presentation npm and the Future of JavaScript. No data is perfect; if you have questions about ours you can read about the methodology used to gather this data.

npm has over 10 million users who download well over 30 billion packages every month. On an average Tuesday—npm’s busiest day—users download more than 1.3 billion packages of open source JavaScript. This gives us a lot of information about what JavaScript users are up to. On top of that data, in partnership with the Node.js Foundation and the JS Foundation we survey of over 16,000 developers to ask what they’re up to.

From these two sources, we’ve uncovered some insights about the makeup of the npm community, as well as information about what the community considers to be best practices. This will help you make your technical choices in 2019.

JavaScript is the world’s most popular programming language

It’s no news to anyone that JavaScript is incredibly popular these days. Stack Overflow’s 2018 developer survey has JavaScript as the most popular programming language (with fellow web languages HTML and CSS at the #2 and #3 spots). GitHub’s most recent Octoverse infographic ranks languages by the number of pull requests received, and JavaScript is the top there, too.

The total number of JavaScript developers is hard to estimate. Slashdata’s 2018 survey suggests there were 9.7M by the end of 2017 and growing quickly, meaning there are well over 10M at this point. npm’s own estimates suggest there are over 10M npm users, and we see similarly rapid growth. There are JavaScript developers who do not yet use npm, but as a percentage of all JavaScript developers they are quite small, possibly fewer than 10%.

The npm Registry contributes to the popularity of JavaScript

Without question, JavaScript’s popularity is driven by its ubiquity as the only language directly usable for developing web applications. However, a fascinating paper by Leo Meyerovich and Ariel Rabkin at Berkeley studied the factors contributing to programming language adoption and found that, overall, the availability of open-source libraries relevant to the task at hand was the most important factor in selecting a programming language.

Our own survey data support the conclusions of this study. The most common reason respondents gave for choosing JavaScript was the number of libraries available.

With over 836,000 libraries currently available, npm is the largest single collection of open-source libraries in the world, by a significant margin—although JavaScript’s tendency towards smaller libraries means this comparison isn’t entirely apples-to-apples. Regardless, this enormous reservoir of open source code means that the popularity of JavaScript and npm works both ways: the language gains popularity because of the Registry, and vice versa.

npm is used to build every kind of application

We asked users where the JavaScript they write is used. An overwhelming 93% of respondents said that they write code for the web, with a still-substantial 70% saying they write JavaScript that runs on servers, i.e., Node.js. However, many other application areas including Internet of Things (IoT), desktop applications, native mobile applications, and others saw substantial numbers of users, too.

This is a significant change for those of us who work at npm, Inc. and maintain the npm command-line tool. npm was invented to serve the needs of server-side app developers, and the needs of web developers are different. Becoming a majority-web platform has meant changing our priorities, which has ledto new features like package locking by default.

npm is essential to web development

When npm, Inc. started in 2014, a tree of a few dozen JavaScript packages was typical. These days, the average modern web application has over 1000 modules, and trees of over 2000 modules are not uncommon. In fact, 97% of the code in a modern web application comes from npm. An individual developer is responsible only for the final 3% that makes their application unique and useful.

This is a huge success story for code reuse, for the strength of the npm community, and for open source in general. The time saved by not re-inventing the code in thousands of modules is saving millions of developers hundreds of millions of coding-hours.

npm has focused on security in 2018

To a great many developers, npm has simply become the way you build a website. This is a responsibility we take seriously. In our survey, 77% of developers said they were concerned about the quality and security of the open source libraries they used, and a worrying 52% said the tools currently available were inadequate. We went into more depth on these results in our post Attitudes to Security in the JavaScript community earlier this year.

In April, we announced that we acquired ^Lift Security and their product, the Node Security Platform. Today, the NSP is integrated directly into npm, and every install of npm includes security audits that notify users if they are installing insecure modules. We also furnish tools to easily correct these vulnerabilities by automatically installing secure versions of their modules. In addition, users of npm Enterprise and paid npm Organizations users receive notifications of embargoed vulnerabilities not yet publicly disclosed.

The demographics of npm users

The basic demographics of our survey respondents are covered in our methodology post, but there are several important facts worth highlighting:

1. We are mostly new. 25% have been using JavaScript for less than 2 years, and 51% have been using npm for less than 2 years. This is a side effect of the community doubling in size in that time!

2. We are mostly self-taught. 69% of npm users mostly taught themselves JavaScript, with the next highest being 22% who learned on the job.

We don’t just write JavaScript. People who use npm aren’t always strictly JavaScript developers—30% each report writing Java, PHP, and Python, and smaller numbers of lots of other languages.

We don’t just work at “tech” companies. 55% of npm users describe themselves as working at a company that wouldn’t be considered a “tech” company.

There are also some ways that npm users don’t differ from the general population of software developers, which is itself interesting. For example, npm users work at every size of company, in roughly the same proportion as those companies exist. JavaScript isn’t a “big company” or a “small company” tech. npm users also are evenly distributed across every industry, as well as other demographics such as age and education level.

Everybody would like less tooling

JavaScript in 2018 is somewhat notorious for requiring a lot of tooling to get going, which is quite a reversal from the situation in 2014, when Node.js was considered an “everything included” framework. Today, most developers wouldn’t consider Node to be a framework at all. True to that, all of our survey respondents would like to see less tooling, less configuration required to get started, and better documentation of the tools that do exist. But what tools?

We went in-depth into the popularity of JavaScript frameworks in our “State of JavaScript Frameworks” series (part 1, part 2, part 3) earlier this year. We won’t reiterate all the findings of that analysis, but rather dive into a few updates of what’s changed in the 9 months since then.

As a reminder, it’s important to understand the “share of registry” metric we are using here: a “flat” graph in this case means strong growth, just not growth relative to the growth of the registry, which is always growing quickly.

React’s growth has slowed

React continues to dominate the web scene. Over 60% of npm’s survey respondents say they are using React, and it has grown further since then. However, that growth in 2018 has been slower than in 2017.

Angular downloads have stayed flat

The two major flavors of Angular combined have stayed roughly flat in terms of market share.

Ember’s popularity has rebounded

In a very unusual phenomenon, Ember’s popularity, which appeared to be declining, has continued a strong rebound. By September, more than twice as many developers were using Ember as at the beginning of the year. We’re going to keep a close eye on this story, but we think Ember’s resurgence is part of the explanation for the slowdown in React.

Vue’s strong growth has continued

Vue was already growing quickly and that continued in 2018. Many Vue users report that they picked it over React because in their opinion it’s easier to get started while maintaining extensibility. Our current theory is that React’s growth has been slowed by many newer users picking Vue.

GraphQL continues hyper-growth

GraphQL, tracked by its most popular client library Apollo, continues to explode in popularity. We think it’s going to be a technical force to reckon with in 2019.

Transpilers rule, led by Babel—and a surprise: TypeScript

Babel is familiar to any React user as the tool used to transpile React’s next-generation JavaScript into the currently-supported JavaScript standards. In line with React’s 60% market share, 65% of npm users report using Babel. (It also has uses outside of the React ecosystem.)

Something of a surprise, however, was TypeScript, with 46% of survey respondents reporting they use Microsoft’s the type-checked JavaScript variant. This is major adoption for a tool of this kind and might signal a sea change in how developers write JavaScript. We are definitely going to be asking more questions about TypeScript usage in the next version of our survey.

npm’s predictions for 2019

It’s always difficult to make predictions about an ecosystem as huge, varied, and fast-changing as JavaScript, but our data has led us to make a few predictions for 2019 that we think we can commit to.

1. You will abandon one of your current tools. Frameworks and tools don’t last in JavaScript. The average framework has a phase of peak popularity of 3–5 years, followed by years of slow decline as people maintain legacy applications but move to newer frameworks for new work. Be prepared to learn new frameworks, and don’t hold on to your current tools too tightly.

2. Despite a slowdown in growth, React will be the dominant framework in 2019. 60% market share for a web framework is unheard-of, and that’s partly because React isn’t a full framework, just part of one. This allows it to flexibly cover more use-cases. But for building a web app in 2019, more people will use React than anything else, and that will result in a big advantage in terms of tutorials, advice, and bug fixes.

3. You’ll need to learn GraphQL. It might be too early to put GraphQL into production, especially if your API is already done, but 2019 is the year you should get your mind around the concepts of GraphQL. There’s a good chance you’ll be using them in new projects later in the year and in 2020.

4. Somebody on your team will bring in TypeScript. 46% adoption implies that TypeScript is more than just a tool for enthusiasts. Real people are getting real value out of the extra safety provided by type-checking. Especially if you’re a member of a larger team, consider adopting TypeScript into your 2019 projects.

Stay tuned

One prediction we’re very confident in making is that this community will continue to rapidly grow and expand the capabilities of JavaScript. As it grows, we’ll be documenting new trends and sharing our insights with the community. You can follow along by subscribing to our weekly newsletter and following us on Twitter.  

[softweb-solutions]

Exploring Node.js 22: Performance Boosts and Exciting New Features

The world of web development is constantly evolving, and Node.js predates this rapidly changing field. Being one of the core technologies in today’s web applications, Node.js advances with each new update, and Node.js 22 is particularly remarkable as it brings many powerful new features and enhancements that every developer will be eager to discover. These updates bring about groundbreaking functionalities for every business aiming to achieve high efficiency, scalability, and innovation in web development.

Since 2009, Node.js has been revolutionary to server-side JavaScript, introducing asynchronous processing and an immense ecosystem that becomes the bedrock for high-performance and scalable applications. Major releases are mainly targeting performance, security improvements, and satisfaction for the developer, as Node.js 22 upholds significant improvements.

A Node.js development company can help you leverage the latest features in Node.js 22 to create applications that are faster, more scalable, and optimized for peak performance. With expert knowledge of each new update, Node.js developers ensure that your projects benefit from the most cutting-edge advancements, providing a solid foundation for innovative, high-quality web solutions.

An overview of Node.js 22

Node.js 22 was released on April 24, 2024, and transitioned into long-term support (LTS) in October 2024. Filled with advancements such as a new V8 engine, a built-in WebSocket client, and enhanced JavaScript features, Node.js 22 gives developers novel ways to build applications that are faster and more efficient than before. This version includes essential improvements such as the Maglev compiler, and new capabilities for running packages. json scripts, enriched add-on APIs, and more — all designed to streamline the development process for Node.js applications.

Let’s dive into the Node.js latest updates and its valuable enhancements. But first, let’s briefly review the preceding and current Node.js versions to provide a solid context for understanding this latest release.

Portfolio

Built a mobile app using full stack development services to monitor air quality

Our client manufactures smart bands to monitor air quality parameters. The data processing performance of their smart band was inadequate. Our front-end full stack developers deployed a mobile solution for them.

Real-time alerts:

The mobile application now gets real-time data from the smart band.

Insights:

The users can check the air quality index (AQI-generated) insights based on collected data.

Assessment:

It facilitates in assessing impacts caused by poor air quality on public health.

Explore Now

Node.js 21 vs. Node.js 22: Is it time to upgrade?

With each version of Node.js introducing meaningful changes, it’s natural to ask whether updating to Node.js 22 is worth it? To assist you in making this decision, the following section provides a quick overview comparing Node.js 21 and Node.js 22 — detailing the key differences and why this upgrade might be beneficial for your projects.

Node.js 21 vs Node.js 22

Node.js version 21

V8 engine: V8 11.8

WebStreams: Supported

ESM modules: Complex process

Test runner: Included

Performance: Effective

Node.js version 22

V8 engine: V8 12.4

WebStreams: Improved support

ESM modules: Default support

Test runner: Accurate

Performance: Enhanced

Key updates in Node.js 22 features

Upgraded V8 engine and the Maglev compiler

Node.js 22 features an updated V8 engine, now version 12.4.254.14, which brings several enhancements, including WebAssembly Garbage Collection Array, new fromAsync, Set methods, and iterator helpers.

In addition, Node.js 22 introduces the V8 Maglev compiler, a just-in-time (JIT) compiler now activated by default, on compatible systems. Positioned between the Turbofan and Sparkplug compilers, Maglev optimizes the performance of short-term CLI programs, providing a notable boost in efficiency for command-line applications.

Support for importing ESM Graphs with require()

A noteworthy addition in Node.js 22 is the ability to import entire ECMAScript module (ESM) graphs using require(). Under the experimental require module, synchronous ESM graphs are now supported. For this to work, the modules must be defined as ES modules in the package.json file with “type”: “module” or by using an .mjs extension, and they must be fully synchronous. This feature streamlines modular JavaScript usage, allowing for efficient, synchronous imports without the need for complex workarounds.

Native WebSocket support

Node.js 22 brings native, browser-compatible WebSocket functionality enabled by default. Previously, developers had to rely on browser-compatible features, but this update simplifies real-time communication and eliminates the need for external WebSocket dependencies, creating a smoother experience for those building web applications that require live data streaming.

glob and globSync functions

The Node.js fs module now includes glob and globSync functions for advanced file pattern matching. These additions allow developers to efficiently find and match file paths according to predefined patterns, enhancing the management and manipulation of file systems in Node.js applications.

Enhanced add-on APIs and environment variable handling

With Node.js 22, developers have access to a comprehensive suite of tools and APIs, including WebSocket, argument parsers, and test runner. These tools enhance the core functionality and eliminate the need for extra components. You also get a text styling API (util.inspect.colors) which offers versatility in text presentation. Environment variable handling has also been streamlined, as developers can now use the — env-file command line option. They can also run commands like util.parseEnv and process.loadEnvFile to manage environment variables more intuitively.

Deprecations in util

Node.js 22 refines its handling of deprecated APIs in the util module. It follows a three-stage deprecation process — documentation-only, runtime, and end-of-life. However, many util APIs were discontinued during runtime in Node.js 22. Developers are advised to run their applications with the — throw-deprecation flag to identify and transition from obsolete APIs, ensuring smoother application performance and compatibility with future versions.

Direct execution of package.json scripts

One of Node.js 22’s useful new features is the ability to run scripts directly from package.json using the command line. The new node-run <script-in-package-json> command makes it easier for developers to execute tasks defined within package.json, adding convenience and reducing the need for additional configurations.

Stabilized Watch Mode Command Line

The latest version of Watch Mode introduces enhancements such as:

watch

watch-path

watch-preserve-output

These options improve the efficiency of the development process by enabling applications to automatically reboot whenever monitored files are modified.

Improved stream performance

Node.js 22 brings optimized stream handling with an increased default high watermark from 16 KiB to 64 KiB, leading to faster stream performance. This update benefits the fetch() API, AbortSignal handling, and the test runner, delivering more responsive applications with minimal memory trade-offs.

How Softweb Solutions can support your transition to Node.js 22

Softweb Solutions holds a strong position in Node.js development services. We can assist your company in smooth transitions into Node.js 22 and benefit from the new updates.

Our team has experience in implementing new features introduced in Node.js in every update, thus delivering high-performance applications with optimized scalability, efficiency, and security. Partner with Softweb Solutions and get applications that are competitive in the dynamic market, and help your business innovate and scale within this really volatile market.

Maximize your project’s potential with Node.js 22

Node.js 22 is a robust upgrade with significant new features and performance boosts, making it a powerful tool for today’s web development needs. Whether you’re currently using Node.js framework or considering the switch, Node.js 22 is worth the exploration for its enhanced efficiency and broader functionality.

To get the most out of this update, partnering with a trusted Node.js development services provider can help you unlock the full potential of these improvements. If you’re ready to elevate your web applications, hire Node.js developers who are well-versed in the latest updates and can bring these advancements to life in your projects. For more information, talk to our experts.

Originally published at softwebsolutions on November 27, 2024.

[lascllow]

Npm install from github tree

NPM INSTALL FROM GITHUB TREE INSTALL

NPM INSTALL FROM GITHUB TREE FREE

You can develop numerous projects with Node.js like single-page applications (SPA), social media applications, static sites, online payment systems, hardware projects, blogs, mobile apps, real-time chat apps, APIs, eCommerce apps, and many more. You don't need to assemble these building blocks from scratch and instead, you can focus on the core of your application.ĭue to other features like Node's efficient caching ability, multiple hosting providers, and cross-platform availability, it's no surprise that it's so popular among developers.

NPM INSTALL FROM GITHUB TREE FREE

If you want to add any feature or building blocks to your application, there's a high probability that an open-source, free library is already available to you. Node.js has one of the largest ecosystems of open source libraries available. Node applications use JavaScript-if you're a frontend developer and know JavaScript, you can reuse those skills and transition to a Full-Stack Developer.

NPM INSTALL FROM GITHUB TREE INSTALL

PS C:UsersshutezDocumentsSimple EmotionCodesedemo.tk> npm install git+ssh://:SimpleEmotion/node-call -analytics.git0.4. It's used in production by large companies like Netflix, LinkedIn, PayPal, Trello, Uber, eBay, NASA, etc. The other 3 repositories have the same format for the install command. It can also be used for building super-fast, highly scalable services. It's easy to get started with Node, and it's great for prototyping and agile development. You can build standalone applications with Node.js, but it's most often used to build back-end services. Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine. What Is Node.js and Why Is it So Popular? Luckily, it's compatible with nearly all operating systems-Windows included.įollow this step-by-step guide to install Node.js and start building your first applications on Windows.

If is provided, it will be used to clone exactly that commit. Authentication module written in TypeScript providing authentication utilities and JWT methods. I am getting following error on npm installġ8 verbose stack TypeError: Cannot read property 'match' of undefined 18 verbose stack at tarballToVersion (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/lib/install/inflate-shrinkwrap.js:87:20) 18 verbose stack at inflatableChild (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/lib/install/inflate-shrinkwrap.js:99:22) 18 verbose stack at /home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/lib/install/inflate-shrinkwrap.js:55:12 18 verbose stack at tr圜atcher (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/node_modules/bluebird/js/release/util.js:16:23) 18 verbose stack at Object.gotValue (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/node_modules/bluebird/js/release/reduce.js:155:18) 18 verbose stack at Object.gotAccum (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/node_modules/bluebird/js/release/reduce.js:144:25) 18 verbose stack at 圜atcher (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/node_modules/bluebird/js/release/util.js:16:23) 18 verbose stack at Promise._settlePromiseFromHandler (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/node_modules/bluebird/js/release/promise.js:517:31) 18 verbose stack at Promise._settlePromise (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/node_modules/bluebird/js/release/promise.js:574:18) 18 verbose stack at Promise._settlePromise0 (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/node_modules/bluebird/js/release/promise.js:619:10) 18 verbose stack at Promise._settlePromises (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/node_modules/bluebird/js/release/promise.js:699:18) 18 verbose stack at _drainQueueStep (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/node_modules/bluebird/js/release/async.js:138:12) 18 verbose stack at _drainQueue (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/node_modules/bluebird/js/release/async.js:131:9) 18 verbose stack at Async._drainQueues (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/node_modules/bluebird/js/release/async.js:147:5) 18 verbose stack at (/home/rahul/.nvm/versions/node/v12.16.3/lib/node_modules/npm/node_modules/bluebird/js/release/async.It may seem obvious, but installing Node.js is the first step to building cool Node.js applications. npm install /: npm install github:/: Install the package at by attempting to clone it using git.

[swimmingeaglestarlight]

Visual Studio Code Apt

Visit the VS Code install page and select the 32 or 64 bit installer. Install Visual Studio Code on Windows (not in your WSL file system). When prompted to Select Additional Tasks during installation, be sure to check the Add to PATH option so you can easily open a folder in WSL using the code command. Visual Studio Code is a free and open-source, cross-platform IDE or code editor that enables developers to develop applications and write code using a myriad of programming languages such as C, C, Python, Go and Java to mention a few. To Install Visual Studio Code on Debian, Ubuntu and Linux Mint: 1. Update your system by running the command. Introduction to Visual Studio Code. Introduction to Visual Studio Code. Skip to Content Current Page: Blog About Contact FAQs. Now, to install the Visual Studio Code DEB package file, run the APT command as follows. $ sudo apt install. / code.deb The APT package manager should start installing the DEB package file. At this point, Visual Studio Code should be installed.

Visual Studio Code Apt

Visual Studio Code Apt Install

Apt Remove Visual Studio Code

Installation

See the Download Visual Studio Code page for a complete list of available installation options.

By downloading and using Visual Studio Code, you agree to the license terms and privacy statement.

Snap

Visual Studio Code is officially distributed as a Snap package in the Snap Store:

You can install it by running:

Once installed, the Snap daemon will take care of automatically updating VS Code in the background. You will get an in-product update notification whenever a new update is available.

Note: If snap isn't available in your Linux distribution, please check the following Installing snapd guide, which can help you get that set up.

Learn more about snaps from the official Snap Documentation.

Debian and Ubuntu based distributions

The easiest way to install Visual Studio Code for Debian/Ubuntu based distributions is to download and install the .deb package (64-bit), either through the graphical software center if it's available, or through the command line with:

Note that other binaries are also available on the VS Code download page.

Installing the .deb package will automatically install the apt repository and signing key to enable auto-updating using the system's package manager. Alternatively, the repository and key can also be installed manually with the following script:

Then update the package cache and install the package using:

RHEL, Fedora, and CentOS based distributions

We currently ship the stable 64-bit VS Code in a yum repository, the following script will install the key and repository:

Then update the package cache and install the package using dnf (Fedora 22 and above):

Or on older versions using yum:

Due to the manual signing process and the system we use to publish, the yum repo may lag behind and not get the latest version of VS Code immediately.

openSUSE and SLE-based distributions

The yum repository above also works for openSUSE and SLE-based systems, the following script will install the key and repository:

Then update the package cache and install the package using:

AUR package for Arch Linux

There is a community-maintained Arch User Repository package for VS Code.

To get more information about the installation from the AUR, please consult the following wiki entry: Install AUR Packages.

Nix package for NixOS (or any Linux distribution using Nix package manager)

There is a community maintained VS Code Nix package in the nixpkgs repository. In order to install it using Nix, set allowUnfree option to true in your config.nix and execute:

Installing .rpm package manually

The VS Code .rpm package (64-bit) can also be manually downloaded and installed, however, auto-updating won't work unless the repository above is installed. Once downloaded it can be installed using your package manager, for example with dnf:

Note that other binaries are also available on the VS Code download page.

Updates

VS Code ships monthly and you can see when a new release is available by checking the release notes. If the VS Code repository was installed correctly, then your system package manager should handle auto-updating in the same way as other packages on the system.

Note: Updates are automatic and run in the background for the Snap package.

Node.js

Node.js is a popular platform and runtime for easily building and running JavaScript applications. It also includes npm, a Package Manager for Node.js modules. You'll see Node.js and npm mentioned frequently in our documentation and some optional VS Code tooling requires Node.js (for example, the VS Code extension generator).

If you'd like to install Node.js on Linux, see Installing Node.js via package manager to find the Node.js package and installation instructions tailored to your Linux distribution. You can also install and support multiple versions of Node.js by using the Node Version Manager.

To learn more about JavaScript and Node.js, see our Node.js tutorial, where you'll learn about running and debugging Node.js applications with VS Code.

Setting VS Code as the default text editor

xdg-open

You can set the default text editor for text files (text/plain) that is used by xdg-open with the following command:

Debian alternatives system

Debian-based distributions allow setting a default editor using the Debian alternatives system, without concern for the MIME type. You can set this by running the following and selecting code:

If Visual Studio Code doesn't show up as an alternative to editor, you need to register it:

Windows as a Linux developer machine

Another option for Linux development with VS Code is to use a Windows machine with the Windows Subsystem for Linux (WSL).

Windows Subsystem for Linux

Visual Studio Code Apt

With WSL, you can install and run Linux distributions on Windows. This enables you to develop and test your source code on Linux while still working locally on a Windows machine. WSL supports Linux distributions such as Ubuntu, Debian, SUSE, and Alpine available from the Microsoft Store.

When coupled with the Remote - WSL extension, you get full VS Code editing and debugging support while running in the context of a Linux distro on WSL.

See the Developing in WSL documentation to learn more or try the Working in WSL introductory tutorial.

Next steps

Once you have installed VS Code, these topics will help you learn more about it:

Additional Components - Learn how to install Git, Node.js, TypeScript, and tools like Yeoman.

User Interface - A quick orientation to VS Code.

User/Workspace Settings - Learn how to configure VS Code to your preferences through settings.

Common questions

Azure VM Issues

I'm getting a 'Running without the SUID sandbox' error?

You can safely ignore this error.

Debian and moving files to trash

If you see an error when deleting files from the VS Code Explorer on the Debian operating system, it might be because the trash implementation that VS Code is using is not there.

Run these commands to solve this issue:

Conflicts with VS Code packages from other repositories

Some distributions, for example Pop!_OS provide their own code package. To ensure the official VS Code repository is used, create a file named /etc/apt/preferences.d/code with the following content:

'Visual Studio Code is unable to watch for file changes in this large workspace' (error ENOSPC)

When you see this notification, it indicates that the VS Code file watcher is running out of handles because the workspace is large and contains many files. Before adjusting platform limits, make sure that potentially large folders, such as Python .venv, are added to the files.watcherExclude setting (more details below). The current limit can be viewed by running:

The limit can be increased to its maximum by editing /etc/sysctl.conf (except on Arch Linux, read below) and adding this line to the end of the file:

The new value can then be loaded in by running sudo sysctl -p.

While 524,288 is the maximum number of files that can be watched, if you're in an environment that is particularly memory constrained, you may wish to lower the number. Each file watch takes up 1080 bytes, so assuming that all 524,288 watches are consumed, that results in an upper bound of around 540 MiB.

Arch-based distros (including Manjaro) require you to change a different file; follow these steps instead.

Another option is to exclude specific workspace directories from the VS Code file watcher with the files.watcherExcludesetting. The default for files.watcherExclude excludes node_modules and some folders under .git, but you can add other directories that you don't want VS Code to track.

I can't see Chinese characters in Ubuntu

We're working on a fix. In the meantime, open the application menu, then choose File > Preferences > Settings. In the Text Editor > Font section, set 'Font Family' to Droid Sans Mono, Droid Sans Fallback. If you'd rather edit the settings.json file directly, set editor.fontFamily as shown:

Package git is not installed

This error can appear during installation and is typically caused by the package manager's lists being out of date. Try updating them and installing again:

The code bin command does not bring the window to the foreground on Ubuntu

Running code . on Ubuntu when VS Code is already open in the current directory will not bring VS Code into the foreground. This is a feature of the OS which can be disabled using ccsm.

Under General > General Options > Focus & Raise Behaviour, set 'Focus Prevention Level' to 'Off'. Remember this is an OS-level setting that will apply to all applications, not just VS Code.

Visual Studio Code Apt Install

Cannot install .deb package due to '/etc/apt/sources.list.d/vscode.list: No such file or directory'

This can happen when sources.list.d doesn't exist or you don't have access to create the file. To fix this, try manually creating the folder and an empty vscode.list file:

Cannot move or resize the window while X forwarding a remote window

If you are using X forwarding to use VS Code remotely, you will need to use the native title bar to ensure you can properly manipulate the window. You can switch to using it by setting window.titleBarStyle to native.

Using the custom title bar

The custom title bar and menus were enabled by default on Linux for several months. The custom title bar has been a success on Windows, but the customer response on Linux suggests otherwise. Based on feedback, we have decided to make this setting opt-in on Linux and leave the native title bar as the default.

Apt Remove Visual Studio Code

The custom title bar provides many benefits including great theming support and better accessibility through keyboard navigation and screen readers. Unfortunately, these benefits do not translate as well to the Linux platform. Linux has a variety of desktop environments and window managers that can make the VS Code theming look foreign to users. For users needing the accessibility improvements, we recommend enabling the custom title bar when running in accessibility mode using a screen reader. You can still manually set the title bar with the Window: Title Bar Style (window.titleBarStyle) setting.

Broken cursor in editor with display scaling enabled

Due to an upstream issue #14787 with Electron, the mouse cursor may render incorrectly with scaling enabled. If you notice that the usual text cursor is not being rendered inside the editor as you would expect, try falling back to the native menu bar by configuring the setting window.titleBarStyle to native.

Repository changed its origin value

If you receive an error similar to the following:

Use apt instead of apt-get and you will be prompted to accept the origin change:

[tak4hir0]

Work can be stressful and we all need a break from time to time. What if you could take that break while having loads of fun and learn a few things at the same time? Well, here’s your chance: we’re excited to release the first multiplayer quiz app built entirely on Salesforce technology! In this blog post, we introduce the Quiz App and share highlights about the app architecture and its deployment. Introducing the Quiz App The quiz app is inspired by the popular Kahoot game. Here’s how it works: First, a game host presents questions from a shared screen or a video projector. Then, players compete by answering those questions in real-time using a mobile web app. The fastest player to give the correct answer scores the most points. As the game progresses, leaderboards are displayed so that players can keep track of scores and ranks. The quiz app was initially launched during Developer Game Night at Dreamforce 2019 with close to a hundred players. Now it’s open source and we’re promoting it during Dreamforce Global Gatherings. That’s right, you can install it for free, inspect the code, and customize it to your liking! Architecture Overview The quiz is divided in two applications: a host app and a player app. The host app is a Lightning Web Component (LWC) app running on a Salesforce Org. The org holds all of the quiz data in custom objects (players, questions, answers…). This means that you can easily import extra questions and customize them. It’s as simple as editing records—zero code change required! The player app is a mobile app built with Lightning Web Components Open Source (LWC OSS). It runs on Node.js deployed on Heroku. There are a few reasons to have the player app on Heroku for our specific use case. First, the Heroku app scales well and can accommodate a large number of users as Heroku limits are based on processing power (dynos) rather than strict governor limits. Secondly, we can easily provide unauthenticated access to our custom app. Unlike Salesforce orgs, there are no user license considerations on Heroku. These advantages do come at a cost: it’s up to us to build the app from the ground up. We use that to our advantage in the quiz player by implementing a lightweight mobile app. Cross-App Communication The two applications communicate with bidirectional REST calls. The player app uses the JSforce library (a JavaScript Salesforce client) to authenticates on the Salesforce org with a username/password flow. The client calls the standard REST APIs as well as a couple of custom Apex REST endpoints. The host app also sends REST requests to the Node.js server of the player app to signal game phase changes (eg: a question becomes available or game results are being displayed). These calls are secured with a shared secret API key that is configured on the two apps during setup. This technique ensures a lightweight and minimal level of security by preventing third parties from accessing the player app REST endpoints. Client-Server Communication on the Player App The player app consists of a client (the LWC OSS app running on a mobile device) and a server (the Node.js backend). The client calls REST APIs on the server to retrieve information like the player’s score. We also establish a WebSocket connection between the client and the server. This allows us to push real-time updates like game phase changes to the mobile app. For example, when a new question can be answered, the Node.js backend broadcasts an WebSocket message to all mobile clients. With that, all players can see game updates at the same time on their mobile devices. While powerful, WebSockets have an important limitation when working on mobile. WebSockets rely on a lasting network connection between the client and the server. On mobile, this connection can easily be broken when the device screen is locked or when the user switches to another app. This means that we must implement some non trivial code to handle reconnection on the client side and a keep alive mechanism to detect and eliminate broken connections on the server side. App Deployment One of the most challenging parts of this project is making sure that the quiz app can be easily deployed by a large number of users with different degrees of technical skill. Given the complexity of the environment (two different technology stacks), we needed to ensure that the deployment is as automated as possible. We rely on two things to achieve that: an org deployment script for the host app and a Heroku deploy button for the player app. Note: the app setup is extensively documented and we even provide a video guide (see link at the end of this post). Org Deployment Script The quiz host app is deployed on a Scratch org with Salesforce DX. This allows us to create a temporary Salesforce org with a lifespan of up to 30 days with a set of commands. These commands are grouped and chained together in a deployment script that you can run with a single command in a terminal. The deployment scripts automates the following tasks: Creating a scratch org Pushing sources to the org Assigning permissions Importing question data Generating a user password Automating the setup process greatly reduces the risk of configuration errors and saves a lot of time. Here’s a simplified version of the deployment script running on MacOs (there’s also an equivalent script for Windows): 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 echo "1. Creating scratch org..." && \ sfdx force:org:create -s -f config/project-scratch-def.json -a $ORG_ALIAS -d 30 && \ echo "" && \ echo "2. Pushing source..." && \ sfdx force:source:push -f -u $ORG_ALIAS && \ echo "" && \ echo "3. Assigning permissions..." && \ sfdx force:user:permset:assign -n Quiz_Host -u $ORG_ALIAS && \ echo "" && \ echo "4. Importing data..." && \ sfdx force:data:tree:import -p data/$DATA/plan.json -u $ORG_ALIAS && \ echo "" && \ echo "5. Generating user password..." && \ sfdx force:user:password:generate -u $ORG_ALIAS && \ echo "" EXIT_CODE="$?" # Check exit code echo "" if [ "$EXIT_CODE" -eq 0 ]; then echo "Installation completed." echo "" sfdx force:org:open -p /lightning/setup/SecurityRemoteProxy/home -u $ORG_ALIAS else echo "Installation failed." fi exit $EXIT_CODE Notice how commands are chained together with the && operator. This executes them one after the other as long as there are no errors. The \ character at the end of the line lets us introduce line breaks for readability. At the end of the script we’re checking for the last command’s exit code with EXIT_CODE="$?". This lets us report the deployment status with a message and open the org if everything went well. Heroku Deploy Button The player app is even easier to install with a Heroku deploy button. The deploy button is an image with a link that the user can click to deploy a Heroku app without leaving the browser. The link URL holds a reference to the GitHub repository that contains the app source code and a deployment configuration file. With the deploy button the user only has to enter a few configuration variables before confirming the deployment. Summary Now that you’ve learned about the Quiz App features and architecture, how about giving it a try? Sign up for a Dreamforce Global Gathering near you to find worthy opponents. Or, explore the code, install the apps, and customize questions by simply editing records. Don’t hesitate to let us know how much fun you had on social media! Resources Quiz app installation instructions

[t-baba]

🎉 JavaScript turns 25 years old

#489 — May 22, 2020

Unsubscribe  :  Read on the Web

JavaScript Weekly

A Complete Walkthrough to Using WebGL — A really thorough walkthrough of getting started with WebGL at the low level, complete with integrated, editable examples and coverage of the math behind 3D rendering. If you’ve ever wondered what libraries like Three.js are using behind the scenes, it’s all here.

Maxime Euzière

Microsoft Unveils 'Azure Static Web Apps' — Azure Static Web Apps brings modern static site deployment to Azure and integrates with GitHub and Visual Studio Code too. Want to see more? Here’s a 6 minute screencast demo. Yet another way to deploy those static single page apps :-)

Microsoft

The Most Complete Spreadsheet for JavaScript Apps – SpreadJS — Deliver true Excel-like experiences with this fast JavaScript enterprise spreadsheet solution. Build FinTech, analysis, budgeting, and forecasting apps. Featuring an Excel I/O, 450+ functions, tables, charts, sparklines, and more. View the latest demo.

SpreadJS by GrapeCity sponsor

The Unreasonable Effectiveness of Declarative Programming — Siddharth shows off his single file animation library by way of showing off the benefits of doing things in an (arguably) declarative style. A nifty post, this, which encourages you to interact with the code yourself.

Siddharth Bhat

The Third Age of JavaScript? — Yes, purely an opinion piece but he might have a point. “Every 10 years there is a changing of the guard in JavaScript. I think we have just started a period of accelerated change that could in future be regarded as the Third Age of JavaScript.”

Shawn Wang

Electron 9.0.0 Released — The popular cross platform desktop app framework gets more dependency bumps and is now running on Chromium 83, V8 8.3, and Node.js 12.14. There’s an integrated PDF viewer now, if you need that.

GitHub Inc.

⚡️ Quick bytes:

JavaScript is 25 years old at.. roughly now!

Microsoft has been showing off its work getting React Native on macOS and some other new Windows features.

Vue has made it into the 'adopt' zone of ThoughtWorks' languages and frameworks technology radar (and Vue 3.0.0 beta 14 is out too.)

Ionic are running IoniConf 2020 online next month (June 24).

💻 Jobs

Senior Software Engineer — Save Lives & Make an Impact — We use Node/TS/React & ML to provide crisis support via SMS. Help us scale globally with a focus on privacy and security.

Crisis Text Line

Find a Job Through Vettery — Vettery specializes in tech roles and is completely free for job seekers. Create a profile to get started.

Vettery

📚 Tutorials and Opinions

▶  (Re)-Implementing The Easiest JavaScript Game Ever — Have you ever played the ‘running dinosaur’ game in Chrome when your connection goes down? This is a fun 8 minutes spent reimplementing the basic mechanic. It’s scrappy, but that’s kinda the point. If you like his style, he’s done a 2 minute video flying through the development of another arcadey game.

KnifeCircus

The Architecture of a Serverless, Vue.js-Powered Content Management System — Not only does this outline the AWS infrastructural architecture pretty well, there’s code for you to use for your own setup if you wish.

Dan Bartlett

Understanding Lazy-Loading in Popular Frontend Frameworks — How Angular, React, and Vue handle on-demand loading of components.

tamos piros

▶  One Developer's Five Most Used JavaScript 'Tricks' — If you’re more at the beginner end of the scale, you might appreciate six minutes spent here. Well presented.

Aaron Jack beginner

Stream Chat API & JavaScript SDK for Custom Chat Apps — Build real-time chat in less time. Rapidly ship in-app messaging with our highly reliable chat infrastructure.

Stream sponsor

5 Differences Between Arrow and Regular Functions — A nice detailed look, with examples, of the differences between arrow and regular functions in JavaScript. I’m sure one or two of these will be new to many of you.

dmitri pavlutin

Dropbox's Great CoffeeScript to TypeScript Migration of 2017 — A deep retrospective from the Dropbox team on migrating hundreds of thousands of lines of CoffeeScript to TypeScript, sharing details on why they chose TypeScript and the challenges faced. “Fast forward to 2020, we now have over two million lines of TypeScript at Dropbox.”

David Goldstein

Promise.all vs Promise.allSettled — “I was reading the MDN docs on JavaScript promises and realized that the difference between Promise.all and Promise.allSettled wasn’t immediately obvious.”

JonLuca DeCaro

Growing Pains: From 0 to 13,000 Dependencies — Find out how your project can go from 0 to 13,000 dependencies in just a few steps.

Nikola Đuza

Error Handling in RxJS

Eugene Ghanizadeh Khoub

A (Mostly) Complete Guide to React Rendering Behavior

Mark Erikson

How to Use Object Destructuring in JavaScript — A code-heavy tutorial looking at object destructuring, a feature introduced in ES6 that allows you to extract properties from objects and bind them to variables.

dmitri pavlutin

🔧 Code & Tools

Reveal.js 4.0: An HTML Presentation Framework — A mature library takes another step forward. The homepage itself is, cleverly, a live demo (use the arrow keys). v4 adds several new features. Just want the code? Here’s the GitHub repo.

Hakim El Hattab

ac-colors: A Reactive Color Conversion and Generation Library — A lot of power under the hood here being able to convert between RGB, HSL, HEX, XYZ, LAB, and LCHab, as well as handle random color generation and contrast ratio calculation.

Vinay

MongoDB Is Easy. Now Make It Powerful. Free Download for 30 Days. — Using MongoDB Atlas? Studio 3T is the professional GUI and IDE that unlocks the power you need.

Studio 3T sponsor

umi-request: A Modern HTTP Request Tool Based on Fetch — An attempt at combining some of the niceties of Axios with the modernity of the Fetch API to get the best of both worlds.

UmiJS

Howler.js: An Audio Library for The Modern Web — Makes things easier cross-platform. Uses the Web Audio API but can fall back to HTML5 Audio.

James Simpson

Vue Class Store: Universal Vue Stores You Write Once and Use Anywhere — We’ll let it speak for itself: “I’ll give you reactivity, computed properties and watches, written in standard JavaScript or TypeScript, with no setup or boilerplate, and you can use me anywhere.”

Dave Stewart

New Integration: PostgreSQL Instrumented for Node.js

AppSignal sponsor

Vue Formulate: The Easy Way to Build Forms with Vue.js — First linked a few months ago, this has come on leaps and bounds since with grouped fields, a way to stop validation, slots for customization, and more.

Braid LLC

NanoPop: A Minimalistic Positioning Engine — In a race to do things in as few bytes as possible, NanoPop aims to be much smaller than even PopperJS for positioning things like tooltips and popovers.

Simon R.

by via JavaScript Weekly https://ift.tt/3bVZAUv

[prevajconsultants]

RT @Iprogrammerinfo: Node.js 14 Adds New Diagnostic Tools @KayEwbank reports that Node.js has been updated with Diagnostic Reports added as a stable feature, a new experimental async local storage API, support for internationalization and easier native module use @nodejs https://t.co/iDIGxIBbDi

Node.js 14 Adds New Diagnostic Tools @KayEwbank reports that Node.js has been updated with Diagnostic Reports added as a stable feature, a new experimental async local storage API, support for internationalization and easier native module use @nodejs https://t.co/iDIGxIBbDi

— I Programmer (@Iprogrammerinfo) April 22, 2020

nodejs

[siva3155]

300+ TOP MongoDB Interview Questions and Answers

MongoDB Interview Questions for freshers experienced :-

1. What is MongoDB? Mongo-DB is a document database which provides high performance, high availability and easy scalability. 2. Which are the different languages supported by MongoDB? MonggoDB provides official driver support for C, C++, C#, Java, Node.js, Perl, PHP, Python, Ruby, Scala, Go and Erlang. You can use MongoDB with any of the above languages. There are some other community supported drivers too but the above mentioned ones are officially provided by MongoDB. 3. What are the different types of NoSQL databases? Give some example. NoSQL database can be classified as 4 basic types: Key value store NoSQL database Document store NoSQL database Column store NoSQL database Graph base NoSQL databse There are many NoSQL databases. MongoDB, Cassandra, CouchBD, Hypertable, Redis, Riak, Neo4j, HBASE, Couchbase, MemcacheDB, Voldemort, RevenDB etc. are the examples of NoSQL databases. 4. Is MongoDB better than other SQL databases? If yes then how? MongoDB is better than other SQL databases because it allows a highly flexible and scalable document structure. For example: One data document in MongoDB can have five columns and the other one in the same collection can have ten columns. MongoDB database are faster than SQL databases due to efficient indexing and storage techniques. 5. What type of DBMS is MongoDB? MongoDB is a document oriented DBMS 6. What is the difference between MongoDB and MySQL? Although MongoDB and MySQL both are free and open source databases, there is a lot of difference between them in the term of data representation, relationship, transaction, querying data, schema design and definition, performance speed, normalization and many more. To compare MySQL with MongoDB is like a comparison between Relational and Non-relational databases. 7. Why MongoDB is known as best NoSQL database? MongoDb is the best NoSQL database because, it is: Document Oriented Rich Query language High Performance Highly Available Easily Scalable 8. Does MongoDB support primary-key, foreign-key relationship? No. By Default, MongoDB doesn't support primary key-foreign key relationship. 9. Can you achieve primary key - foreign key relationships in MongoDB? We can achieve primary key-foreign key relationship by embedding one document inside another. For example: An address document can be embedded inside customer document. 10. Does MongoDB need a lot of RAM? No. There is no need a lot of RAM to run MongoDB. It can be run even on a small amount of RAM because it dynamically allocates and de-allocates RAM according to the requirement of the processes.

MongoDB Interview Questions 11. Explain the structure of ObjectID in MongoDB. ObjectID is a 12-byte BSON type. These are: 4 bytes value representing seconds 3 byte machine identifier 2 byte process id 3 byte counter 12. Is it true that MongoDB uses BSON to represent document structure? Yes. 13. What are Indexes in MongoDB? In MondoDB, Indexes are used to execute query efficiently. Without indexes, MongoDB must perform a collection scan, i.e. scan every document in a collection, to select those documents that match the query statement. If an appropriate index exists for a query, MongoDB can use the index to limit the number of documents it must inspect. 14. By default, which index is created by MongoDB for every collection? By default, the_id collection is created for every collection by MongoDB. 15. What is a Namespace in MongoDB? Namespace is a concatenation of the database name and the collection name. Collection, in which MongoDB stores BSON objects. 16. Can journaling features be used to perform safe hot backups? Yes. 17. Why does Profiler use in MongoDB? MongoDB uses a database profiler to perform characteristics of each operation against the database. You can use a profiler to find queries and write operations 18. If you remove an object attribute, is it deleted from the database? Yes, it be. Remove the attribute and then re-save(. the object. 19. In which language MongoDB is written? MongoDB is written and implemented in C++. 20. Does MongoDB need a lot space of Random Access Memory (RAM)? No. MongoDB can be run on small free space of RAM. 21. What language you can use with MongoDB? MongoDB client drivers supports all the popular programming languages so there is no issue of language, you can use any language that you want. 22. Does MongoDB database have tables for storing records? No. Instead of tables, MongoDB uses "Collections" to store data. 23. Do the MongoDB databases have schema? Yes. MongoDB databases have dynamic schema. There is no need to define the structure to create collections. 24. What is the method to configure the cache size in MongoDB? MongoDB's cache is not configurable. Actually MongoDb uses all the free spaces on the system automatically by way of memory mapped files. 25. How to do Transaction/locking in MongoDB? MongoDB doesn't use traditional locking or complex transaction with Rollback. MongoDB is designed to be light weighted, fast and predictable to its performance. It keeps transaction support simple to enhance performance. 26. Why 32 bit version of MongoDB are not preferred ? Because MongoDB uses memory mapped files so when you run a 32-bit build of MongoDB, the total storage size of server is 2 GB. But when you run a 64-bit build of MongoDB, this provides virtually unlimited storage size. So 64-bit is preferred over 32-bit. 27. Is it possible to remove old files in the moveChunk directory? Yes, These files can be deleted once the operations are done because these files are made as backups during normal shard balancing operation. This is a manual cleanup process and necessary to free up space. 28. What will have to do if a shard is down or slow and you do a query? If a shard is down and you even do query then your query will be returned with an error unless you set a partial query option. But if a shard is slow them Mongos will wait for them till response. 29. Explain the covered query in MongoDB. A query is called covered query if satisfies the following two conditions: The fields used in the query are part of an index used in the query. The fields returned in the results are in the same index. 30. What is the importance of covered query? Covered query makes the execution of the query faster because indexes are stored in RAM or sequentially located on disk. It makes the execution of the query faster. Covered query makes the fields are covered in the index itself, MongoDB can match the query condition as well as return the result fields using the same index without looking inside the documents. 31. What is sharding in MongoDB? In MongoDB, Sharding is a procedure of storing data records across multiple machines. It is a MongoDB approach to meet the demands of data growth. It creates horizontal partition of data in a database or search engine. Each partition is referred as shard or database shard. 32. What is replica set in MongoDB? A replica can be specified as a group of mongo instances that host the same data set. In a replica set, one node is primary, and another is secondary. All data is replicated from primary to secondary nodes. 33. What is primary and secondary replica set in MongoDB? In MongoDB, primary nodes are the node that can accept write. These are also known as master nodes. The replication in MongoDB is single master so, only one node can accept write operations at a time. Secondary nodes are known as slave nodes. These are read only nodes that replicate from the primary. 34. By default, which replica sets are used to write data? By default, MongoDB writes data only to the primary replica set. 35. What is CRUD in MongoDB? MongoDB supports following CRUD operations: Create Read Update Delete 36. In which format MongoDB represents document structure? MongoDB uses BSON to represent document structures. 37. What will happen when you remove a document from database in MongoDB? Does MongoDB remove it from disk? Yes. If you remove a document from database, MongoDB will remove it from disk too. 38. Why are MongoDB data files large in size? MongoDB doesn't follow file system fragmentation and pre allocates data files to reserve space while setting up the server. That's why MongoDB data files are large in size. 39. What is a storage engine in MongoDB? A storage engine is the part of a database that is used to manage how data is stored on disk. For example: one storage engine might offer better performance for read-heavy workloads, and another might support a higher-throughput for write operations. 40. Which are the storage engines used by MongoDB? MMAPv1 and WiredTiger are two storage engine used by MongoDB. 41. What is the usage of profiler in MongoDB? A database profiler is used to collect data about MongoDB write operations, cursors, database commands on a running mongod instance. You can enable profiling on a per-database or per-instance basis. The database profiler writes all the data it collects to the system. profile collection, which is a capped collection. 42. Is it possible to configure the cache size for MMAPv1 in MongoDB? No. it is not possible to configure the cache size for MMAPv1 because MMAPv1 does not allow configuring the cache size. 43. How to configure the cache size for WiredTiger in MongoDB? For the WiredTiger storage engine, you can specify the maximum size of the cache that WiredTiger will use for all data. This can be done using storage.wiredTiger.engineConfig.cacheSizeGB option. 44. How does MongoDB provide concurrency? MongoDB uses reader-writer locks for concurrency. Reader-writer locks allow concurrent readers shared access to a resource, such as a database or collection, but give exclusive access to a single write operation. 45. What is the difference between MongoDB and Redis database? Difference between MongoDB and Redis: Redis is faster than MongoDB. Redis has a key-value storage whereas MongoDB has a document type storage. Redis is hard to code but MongoDB is easy. 46. What is the difference between MongoDB and CouchDB? Difference between MongoDB and CouchDB: MongoDB is faster than CouchDB while CouchDB is safer than MongoDB. Triggers are not available in MongoDB while triggers are available in CouchDB. MongoDB serializes JSON data to BSON while CouchDB doesn't store data in JSON format. 47. What is the difference between MongoDB and Cassandra? Difference between MongoDB and Cassandra: MongoDB is cross-platform document-oriented database system while Cassandra is high performance distributed database system. MongoDB is written in C++ while Cassandra is written in Java. MongoDB is easy to administer in the case of failure while Cassandra provides high availability with no single point of failure. 48. Is there any need to create database command in MongoDB? You don't need to create a database manually in MongoDB because it creates automaically when you save the value into the defined collection at first time. 49. What do you understand by NoSQL databases? Is MongoDB a NoSQL database? explain. At the present time, the internet is loaded with big data, big users, big complexity etc. and also becoming more complex day by day. NoSQL is answer of all these problems, It is not a traditional database management system, not even a relational database management system (RDBMS). NoSQL stands for "Not Only SQL". NoSQL is a type of database that can handle and sort all type of unstructured, messy and complicated data. It is just a new way to think about the database. Yes. MongoDB is a NoSQL database. MongoDB Questions and Answers Pdf Download Read the full article