#Java-StringBuffer

[herovired12]

StringBuffer and StringBuilder in Java are classes used to create mutable strings. StringBuffer is synchronized, making it thread-safe but slower, which is ideal for multi-threaded environments. In contrast, StringBuilder is not synchronized, offering better performance in single-threaded scenarios. Both allow dynamic string manipulation and are more efficient than immutable String objects. Check here to learn more.

[tinchicus]

Esta funcion nos agrega el contenido de un objeto Matcher a uno de tipo StringBuffer. Espero les sea de utilidad!

[codezup]

Optimize Java String Concatenation for Better Performance

1. Introduction String concatenation in Java is a critical area for performance optimization. Because Java strings are immutable, repeated concatenation can lead to inefficiencies. This tutorial will guide you through best practices to optimize string concatenation using StringBuilder and StringBuffer, and provide hands-on examples. What you’ll learn: – Avoiding inefficient concatenation –…

[surajkumasblog]

How to Convert Char to String in Java

In Java, converting a char to a String is a common task when working with characters and strings. Since Java provides several ways to accomplish this, it is essential to choose the most efficient method based on the use case. In this article, we will explore various how to convert char to string in java.

Using Character.toString(char) Method The simplest and most readable way to convert a char to a String is by using the Character.toString(char) method.

java Copy Edit char ch = 'A'; String str = Character.toString(ch); System.out.println(str); // Output: A This method is easy to use and ensures that the char is properly converted into a String.

Using String Concatenation (+) Another straightforward way to convert a char to a String is by concatenating it with an empty string ("").

java Copy Edit char ch = 'B'; String str = ch + ""; System.out.println(str); // Output: B This method is commonly used because of its simplicity, but it might not be the most efficient in terms of performance.

Using String.valueOf(char) Method The String.valueOf(char) method is another efficient way to convert a char to a String.

java Copy Edit char ch = 'C'; String str = String.valueOf(ch); System.out.println(str); // Output: C This method is preferred in performance-critical applications as it is optimized internally.

Using new String(charArray) Constructor You can also convert a char to a String by first placing it inside a character array and then using the String constructor.

java Copy Edit char ch = 'D'; String str = new String(new char[]{ch}); System.out.println(str); // Output: D This method is useful when working with arrays but is generally not recommended for simple char to String conversions due to unnecessary object creation.

Using StringBuilder or StringBuffer For scenarios where you need to frequently append characters to a string, using StringBuilder or StringBuffer is more efficient.

java Copy Edit char ch = 'E'; StringBuilder sb = new StringBuilder(); sb.append(ch); String str = sb.toString(); System.out.println(str); // Output: E This method is useful when constructing strings dynamically in loops or handling multiple characters efficiently.

Conclusion Converting a char to a String in Java is simple and can be done in multiple ways. The best method depends on readability, efficiency, and use case:

Use Character.toString(char) or String.valueOf(char) for clean and efficient conversion. Use + "" if you need a quick and simple approach. Avoid unnecessary object creation unless required, as in new String(charArray). Use StringBuilder when dealing with multiple characters dynamically.

[sunbeaminfo]

Enhance Your Programming Skills with Core Java Classes at Sunbeam Institute, Pune

Elevate your programming expertise with our comprehensive Core Java classes at Sunbeam Institute of Information Technology in Pune. Designed for students, freshers, and working professionals, our course offers in-depth knowledge of Java, from fundamental concepts to advanced techniques.

Course Highlights:

Batch Schedule: January 25, 2025 – February 17, 2025

Duration: 80 hours

Timings: 9:00 AM to 1:00 PM (Monday to Saturday)

Mode: Online and Offline options available

Fees: ₹7,500 (Online) | ₹8,000 (Offline) (Including 18% GST)

Course Syllabus:

Java Language Fundamentals: Understand Java language features, JDK, JRE, JVM, data types, and more.

Object-Oriented Programming Concepts: Learn about classes, inheritance, polymorphism, and interfaces.

Exception Handling: Master error handling, custom exceptions, and chained exceptions.

Functional Programming Fundamentals: Explore lambda expressions, functional interfaces, and method references.

Generics: Delve into parameterized types, bounded type parameters, and generic methods.

String Handling: Work with String, StringBuffer, StringBuilder, and regular expressions.

Collection Framework: Study lists, sets, maps, and Java 8 streams.

Multithreading: Understand thread life cycle, synchronization, and concurrency issues.

File I/O: Learn about file processing, serialization, and deserialization.

Reflection: Gain insights into metadata, dynamic method invocation, and reflection classes.

Why Choose Sunbeam Institute?

Sunbeam Institute is renowned for its experienced instructors and practical approach to learning. Our Core Java course is tailored to equip you with the skills necessary to excel in the software development industry. Whether you're beginning your programming journey or aiming to enhance your existing skills, our structured curriculum and hands-on training will support your career growth.

Enroll Now:

Don't miss this opportunity to advance your programming skills. Enroll in our Core Java classes today and take the next step in your career.

For more details and registration, visit our https://sunbeaminfo.in/modular-courses/core-java-classes Note: Limited seats are available. Early registration is recommended to secure your spot.

[cybersuccesss]

Achieve Java Excellence: With Java Course in Pune at Cyber Success

Elevate Your Java Skills: Advanced Java Course in Pune at Cyber Success

In the ever-evolving technological world, mastering programming languages ​​is the key to unlocking a successful career. Java programming is known for its versatility and scalability, popular among developers. One of the most powerful tools in the Java Developer Toolkit is the ability to handle string operations efficiently. At Cyber ​​Success Institute, we offer the Best Java course in Pune that will prepare you for Java programming from basic concepts to advanced concepts, advanced wiring and adaptation to real-world challenges. String is the backbone of many applications, and understanding how to work with them is important for any aspiring full-stack developer. Whether you’re developing a web application, mobile application, or enterprise solution, handling threads effectively can make your code more robust and efficient. Whether you are a beginner in programming or an experienced person who wants to expand your skills, our Java course in Pune is suitable for everyone.

Learn Essential String Operations: The Art of Coding with Java Classes in Pune

String are everywhere in programming. From user input to data processing and output generation, they play an important role. Whether you’re developing a web application, mobile application, or enterprise solution, handling threads effectively can make your code more robust and efficient. Understanding string functions requires you to consider the beauty and power of Java programming. At the Cyber ​​Success Institute, our Advanced Java Classes in Pune cover a wide variety of string functions that are fundamental to coding success. Every application consists of data, and strings are often used to represent and manipulate this data. From simple text conversions to complex data parsing, string operations empower developers to extract, transform, and organize data as needed. Skills in string manipulation allow you to efficiently manipulate data, whether you’re working with JSON, XML, CSV, or other data formats, making your applications more flexible and robust.

Features Of Strings with Java Training Classes in Pune at Cyber Success

At The Cyber ​​Success Institute, our advanced Java courses cover a wide variety of string functions that are fundamental to coding success:

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String Length: Understanding how to measure and manage string length, which is fundamental to data processing.

String Replacement: Learn to find ways to replace characters or sequences in a string, while maintaining data integrity with Java Course in Pune at Cyber Success.

Case Conversion: It is the ability to change string cases easily, ensuring consistency and accuracy across all your applications.

Unlock New Possibilities with Advanced String Manipulation with Java Classes in Pune

Strings play an important role in the creation of dynamic web pages, emails, reports, and more. Through the proper use of strings, templates and layouts, you can tailor content to the user’s preferences and behaviors, enhancing the overall user experience and engagement. At Cyber Success Institute, we believe in empowering education. Our Java course in Pune goes beyond the basics and goes deeper into string efficiency Go to those who take your coding to new heights:

Regular comment: Use the power of regex for incredible pattern consistency and accuracy.

StringBuilder and StringBuffer: Optimize your string processing for performance and efficiency.

Unicode and Encoding: Embrace internationalization and develop applications for a global audience.

Immutable strings: Take the concept of immutability and use it to write more secure and reliable code.

Why Choose Cyber Success for Java Training Classes in Pune?

At The Cyber ​​Success Institute, we believe in empowering education. We have designed our syllabus for Java course in Pune with industry experts to equip you with the skills and knowledge to develop a deep understanding of Java programming. Choosing Cyber ​​Success Institute means embracing practical, hands-on experience guided by industry experts. Our comprehensive, curriculum of Java course covers everything from basic to advanced Java topics, ensuring you have the skills you need for real-world applications. We focus on your career development through resume building, interview preparation and solid professional support. We cater to your unique needs with flexible learning methods and personalized attention. Join us to unlock your potential and start a successful career in Java development.

Here are some features of the Java Course in Pune at Cyber Success Institute

Expert Trainers: At Cyber Success, our trainers are industry experts with extensive experience in Java development. They bring their wealth of knowledge and practical insights to the classroom, providing you with a rich and relevant learning experience. Their guidance will help you navigate the complexities of Java programming, making your learning journey easier and more enjoyable.

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[some-programming-pearls]

What is the difference between String, StringBuilder, and StringBuffer Classes? Any other alternative classes for String manipulation?

In Java, String, StringBuilder, and StringBuffer are classes used for string manipulation, but they have differences in terms of mutability, performance, and thread safety: String: Immutable: Once an String object is created, its value cannot be changed. Thread-safe: Since strings are immutable, they are inherently thread-safe. Suitable for scenarios where the content of the string doesn’t…

[rohit-69]

Java String Operations: Unraveling the Magic

An IntroductionStrings are the fundamental building blocks of all computer languages. They save text, characters, and even our personal sentiments for the digital universe. Strings in Java are more than simply a collection of letters; they are flexible objects with special abilities. Buckle up as we journey through the wonderful world of string operations!

Creating Strings Before we go into the details, let's look at how strings are created. There are two methods for creating a string object:

1.String Literal: Imagine string literals as miniature magic spells. When you declare a string with double quotes, Java examines its mysterious "string constant pool." If the identical spell (string) already exists there, it will provide you a reference to it. Otherwise, a new magical instance is summoned. For example: '''java String s1 = "hello"; // Makes a reference to the existing "hello" spell. String s2 = "hello"; // Reuse the same spell (no new instance) '''

2. Using the 'new' keyword: Sometimes we need new spells. When you use 'new' to generate a string, Java creates a new instance in ordinary heap memory. The literal is still present in the continuous pool. For example: '''java String s3 = new String("world"); // Creates a new instance on the heap '''

Common String Operation

Now that we have summoned So, let's use our wands (or keyboards) to perform some magic:

1. Concatenation: Joining strings is similar to mixing potions. Use the '+' operator to merge them. '''java string fullName = firstName + " " + lastName; // "Harry Potter" '''

2. Length: Interested in the length of your incantation? The 'length()' technique reveals the following: '''java int spellLength = fullName.length(); // 12 '''

3. Comparison: To determine whether two spells are equal, use 'equals()' or 'compareTo()': '''java boolean sameSpell = s1.equals(s2); // True integer spellComparison = s1.compareTo(s2); '''

4. Substring: Extract a piece of the spellbook: '''java string potion = fullName.substring(6); // "Potter" '''

5. Replacing Ingredients: Replace ingredients with'replace()'. '''java: String newSpell = fullName.Replace "Harry" with "Hermione Potter".

6. Splitting Spells: Split a large spell into a series of smaller ones. '''java String[] words = fullName.split(" "); // ["Harry", "Potter"] '''

Why String Magic Matters

- Immutability: Strings, like ancient scrolls, do not alter once written. This immutability assures that your magical code remains stable. - String Pool: The constant pool conserves memory by reusing existing spells. Efficiency at its best! - StringBuilder and StringBuffer: These classes come in handy when mutable spells are required (for example, dynamic incantations).

Conclusion

Strings in Java are more than just words; they are the incantations that define our digital magic. Whether you're concatenating, comparing, or separating, keep in mind that each string tells a story made up of characters and bytes.

So go forth, young wizard, and use your strings wisely. May your code be bug-free and your magic enchanting! 🌟✨

if you want to know more about this topic or any other topic you can visit analyticsjobs.in or click here

[herovired12]

StringBuffer in Java is a class that provides methods to manipulate and modify strings. It offers various methods such as append, insert, delete, and more. It is mutable, meaning it can be modified after creation. This makes it useful for tasks that involve a lot of string manipulation. Hero Vired provides comprehensive examples to help you understand its usage effectively. For More Information, Please Visit The Blog.

[javatarainingtipsandtrick]

How to optimize memory in Java?

Optimizing memory usage in Java training near me is essential to ensure efficient and responsive applications while minimizing the risk of memory-related issues like Out Of Memory Errors. Here are several strategies to optimize memory in Java

Use Data Structures Wisely

Choose the appropriate data structures for your application's needs. Efficient data structures can significantly reduce memory consumption.

For example, use ArrayList when the size is dynamic but known in advance and HashSet or HashMap when you need fast lookup operations.

Minimize Object Creation

Excessive object creation can lead to high memory usage and increased garbage collection overhead. Reuse objects whenever possible.

Consider using object pooling or object reclamation techniques to reduce object churn.

String Handling

Be mindful of string concatenation operations, as they can create many temporary string objects. Use StringBuilder or StringBuffer for efficient string concatenation.

If you have many identical strings, consider using string interning to reuse string instances.

Avoid Memory Leaks

Be cautious about holding references to objects longer than necessary. Ensure that objects are eligible for garbage collection when they are no longer needed.

Use weak references or soft references when appropriate to allow objects to be collected more easily.

Use Primitive Data Types

Whenever possible, use primitive data types (int, float, char, etc.) instead of their object counterparts (Integer, Float, Character, etc.) to save memory.

Array Optimization

Use arrays instead of collections (e.g., ArrayList) when the size is known and fixed, as arrays have a smaller memory overhead.

Be cautious with multi-dimensional arrays, as they can consume more memory than expected due to padding.

Memory Profiling

Use memory profiling tools to identify memory leaks and memory-hungry parts of your application. Tools like VisualVM or YourKit can help pinpoint memory issues.

Garbage Collection Tuning

Tune the garbage collection settings using JVM flags (e.g., -Xmx, -Xms, -XX:MaxHeapFreeRatio, -XX:MinHeapFreeRatio, etc.) to optimize heap memory management.

[surajkumasblog]

How to Convert Character to String in Java

In Java, converting a character (char) to a string (String) is a common operation. Java provides multiple ways to achieve this, each suitable for different use cases. This article how to convert character to string in java a character into a string efficiently.

Using Character.toString(char c)

Java provides a built-in method Character.toString(char c) that converts a character into a string.

Example: char ch = 'A'; String str = Character.toString(ch); System.out.println(str); // Output: A This method is simple and recommended for converting a single character to a string.

Using String Concatenation

You can concatenate an empty string ("") with a character to convert it into a string.

Example: char ch = 'B'; String str = "" + ch; System.out.println(str); // Output: B This approach is widely used because of its simplicity and readability.

Using String.valueOf(char c)

The String.valueOf() method is another way to convert a character to a string in Java.

Example: This approach is widely used because of its simplicity and readability.

Using String.valueOf(char c)

The String.valueOf() method is another way to convert a character to a string in Java.

Example: This approach is widely used because of its simplicity and readability.

Using String.valueOf(char c)

The String.valueOf() method is another way to convert a character to a string in Java.

Example:

Using Character Wrapper Class and toString() Method

Java allows using the Character wrapper class with the toString() method to convert a character to a string.

Example:

Character ch = 'D'; String str = ch.toString(); System.out.println(str); // Output: D This method is useful when dealing with Character objects instead of primitive char values.

Using StringBuilder or StringBuffer

If you are dealing with multiple character conversions, using StringBuilder or StringBuffer can be efficient.

Example: char ch = 'E'; StringBuilder sb = new StringBuilder(); sb.append(ch); String str = sb.toString(); System.out.println(str); // Output: E This approach is useful when working with dynamic strings that require multiple modifications.

Conclusion

Converting a character to a string in Java is straightforward and can be achieved using various methods, including:

Character.toString(char c)

String concatenation ("" + char)

String.valueOf(char c)

Character.toString()

StringBuilder or StringBuffer

[sunbeaminfo]

Elevate your programming expertise with our comprehensive Core Java classes at Sunbeam Institute of Information Technology in Pune. Designed for students, freshers, and working professionals, our course offers in-depth knowledge of Java, from fundamental concepts to advanced techniques.

Course Highlights:

Batch Schedule: January 25, 2025 – February 17, 2025

Duration: 80 hours

Timings: 9:00 AM to 1:00 PM (Monday to Saturday)

Mode: Online and Offline options available

Fees: ₹7,500 (Online) | ₹8,000 (Offline) (Including 18% GST)

Course Syllabus:

Java Language Fundamentals: Understand Java language features, JDK, JRE, JVM, data types, and more.

Object-Oriented Programming Concepts: Learn about classes, inheritance, polymorphism, and interfaces.

Exception Handling: Master error handling, custom exceptions, and chained exceptions.

Functional Programming Fundamentals: Explore lambda expressions, functional interfaces, and method references.

Generics: Delve into parameterized types, bounded type parameters, and generic methods.

String Handling: Work with String, StringBuffer, StringBuilder, and regular expressions.

Collection Framework: Study lists, sets, maps, and Java 8 streams.

Multithreading: Understand thread life cycle, synchronization, and concurrency issues.

File I/O: Learn about file processing, serialization, and deserialization.

Reflection: Gain insights into metadata, dynamic method invocation, and reflection classes.

Why Choose Sunbeam Institute?

Sunbeam Institute is renowned for its experienced instructors and practical approach to learning. Our Core Java course is tailored to equip you with the skills necessary to excel in the software development industry. Whether you're beginning your programming journey or aiming to enhance your existing skills, our structured curriculum and hands-on training will support your career growth.

Enroll Now:

Don't miss this opportunity to advance your programming skills. Enroll in our Core Java classes today and take the next step in your career.

[techgiantblog]

Java - StringBuffer vs StringBuilder

Java – StringBuffer vs StringBuilder

In this article we’ll first look at some important characteristics of String. Subsequently we’ll have a look at how StringBuffer and StringBuilder helps on String operations and also we’ll discuss about similarities and differences between them.

String – Important characteristics

String is immutable. So it is suitable to be used in multi-threaded environment.

String is a final class. All…

[some-programming-pearls]

What is the best way to create and use String variables in Java?

The best way to create and use String variables in Java depends on the specific requirements and context of your application. Here are some general best practices: Use String Literal: When creating String variables with fixed values, use string literals directly. This is the simplest and most common way to create strings. String greeting = "Hello, world!"; Use StringBuilder or StringBuffer for…

[techandguru-blog]

There are times when we do not know the exact item but we know how it looks like i.e. it has specific pattern and certain characteristics. So by just knowing the pattern, we can identify the items. In the same way, there are patterns to identify strings or set of strings in given text or file in java. For that, we have a REGULAR EXPRESSION in java. e.g. if we want to catch all email from the given text, we know how emails look like so we can define a pattern. We create a regex to represent that pattern. And performing pattern match on the given text, we can list all the emails in the given input text.

So regular expression is a special sequence of character that helps to match, find, edit other string or set of strings in the given input, using a specialized string held in so-called Pattern. The regular expression in java is provided through java.util.regex package. Java.util.regex primarily contains three classes name listed below

- Pattern Class: It is used to define the patterns for matching. An object of Pattern class represents a compiled representation of the regular expression. There is no public constructor available to create an object of Pattern class. To instantiate an object of Pattern class, one has to use any version of public static compile() method of Pattern class. These methods accept regular expression string as the first argument.

- Matcher Class: Matcher class is an engine to interpret the pattern of regular expression and performs the match on the input string. Matcher class too does not have any public constructor. To obtain an object of Matcher class, one has to use call matcher() method on Pattern Class object.

- PatternSyntaxException Class: A PatternSyntaxException class represents an unchecked exception that indicates a Syntax error in the regular expression.

CAPTURING GROUP in Regular Expression

The capturing group represents the group of the letter put together as a single unit. They are created by putting letters to be grouped in parentheses. e.g. (techie360).

Capturing groups are numbered by counting the opening parentheses from left to right. e.g ((t)(pq)) has capturing group in the order ((t)(pq)), (t), (pq).

To find the number of capturing group in the regular expression, just use groupCount() method on Matcher class object. Every capturing group contains group 0 which is not included in the count returned by groupCount().

Example of Capturing Group usage

import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexMatches { public static void main( String args[] ) { // input String String line = "you are reading post on techie360!"; String pattern = "(.*)(\\d+)(.*)"; // Create a Pattern object Pattern p = Pattern.compile(pattern); // Now create matcher object. Matcher m = p.matcher(line); if (m.find( )) { System.out.println("Found value: " + m.group(0) ); System.out.println("Found value: " + m.group(1) ); System.out.println("Found value: " + m.group(2) ); }else { System.out.println("NO MATCH"); } } }

The output of the above program would be

Found value: you are reading post on techie360! Found value: you are reading post on techie360! Found value: 0

REGULAR EXPRESSION SYNTAX AND MEANING

In the below table, a complete list of regular expression letters are listed

Regex Meaning ^ Matches the beginning of the line. $ Matches the end of the line. . Matches any single character except a newline. Using m option allows it to match the newline as well. [...] Matches any single character in brackets. [^...] Matches any single character not in brackets. \A Beginning of the entire string. \z End of the entire string. \Z End of the entire string except for allowable final line terminator. re* Matches 0 or more occurrences of the preceding expression. re+ Matches 1 or more of the previous thing. re? Matches 0 or 1 occurrence of the preceding expression. re{ n} Matches exactly n number of occurrences of the preceding expression. re{ n,} Matches n or more occurrences of the preceding expression. re{ n, m} Matches at least n and at most m occurrences of the preceding expression. a| b Matches either a or b. (re) Groups regular expressions and remembers the matched text. (?: re) Groups regular expressions without remembering the matched text. (?> re) Matches the independent pattern without backtracking. \w Matches the word characters. \W Matches the nonword characters. \s Matches the whitespace. Equivalent to [\t\n\r\f]. \S Matches the non-whitespace. \d Matches the digits. Equivalent to [0-9]. \D Matches the non-digits. \A Matches the beginning of the string. \Z Matches the end of the string. If a newline exists, it matches just before newline. \z Matches the end of the string. \G Matches the point where the last match finished. \n Back-reference to capture group number "n". \b Matches the word boundaries when outside the brackets. Matches the backspace (0x08) when inside the brackets. \B Matches the nonword boundaries. \n, \t, etc. Matches newlines, carriage returns, tabs, etc. \Q Escape (quote) all characters up to \E. \E Ends quoting begun with \Q.

METHODS OF MATCHER CLASS

Matcher class methods can be divided into three categories basis the function they perform:

- Index Methods: index methods provide the index of match found in the input string. Below is the list of index methods:

Method Explanation public int start() Returns the start index of the previous match. public int start(int group) Returns the start index of the subsequence captured by the given group during the previous match operation. public int end() Returns the offset after the last character matched. public int end(int group) Returns the offset after the last character of the subsequence captured by the given group during the previous match operation.

- Study Methods: these methods perform match on the input string and return whether the match is found or not. Please see below list for all Study methods:

Method Description Public boolean lookingAt() Attempts to match the input sequence, starting at the beginning of the region, against the pattern. public boolean find() Attempts to find the next subsequence of the input sequence that matches the pattern. public boolean find(int start) Resets this matcher and then attempts to find the next subsequence of the input sequence that matches the pattern, starting at the specified index. public boolean matches() Attempts to match the entire region against the pattern.

REPLACEMENT METHODS:

These methods perform replacement in the input string. Below are replacement methods

Method & Description public Matcher appendReplacement(StringBuffer sb, String replacement) Implements a non-terminal append-and-replace step. public StringBuffer appendTail(StringBuffer sb) Implements a terminal append-and-replace step. public String replaceAll(String replacement) Replaces every subsequence of the input sequence that matches the pattern with the given replacement string. public String replaceFirst(String replacement) Replaces the first subsequence of the input sequence that matches the pattern with the given replacement string. public static String quoteReplacement(String s) Returns a literal replacement String for the specified String. This method produces a String that will work as a literal replacement s in the appendReplacement method of the Matcher class.

matches() and lookingAt() methods: Similarity and differences

- both methods match pattern in the input string

- both start matching at the start of input string

- matches() requires complete string to be matched but lookingAt() does not require the complete string to be matching.

To demonstrate the difference see the example below:

import java.util.regex.Pattern; import java.util.regex.Matcher; public class RegexMatches { private static final String REGEX = "too"; private static final String INPUT = "tooo"; private static Pattern pattern; private static Matcher matcher; public static void main( String args[] ) { pattern = Pattern.compile(REGEX); matcher = pattern.matcher(INPUT); System.out.println("REGEX is: "+REGEX); System.out.println("INPUT is: "+INPUT); System.out.println("lookingAt(): "+matcher.lookingAt()); System.out.println("matches(): "+matcher.matches()); } }

the output of the above program

REGEX is: foo INPUT is: fooooooooooooooooo lookingAt(): true matches(): false

- replaceFirst( ) replaces first matching occurrence and replaceAll() replaces all occurrences of the pattern matching.

So we understand how we can use regular expression in java for pattern matching. Regular expressions are quite a powerful tool in java to find, edit and replace the input string.

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