Java Strings

Java Strings

What are Strings?

In the Article, we will Discuss about the Strings of java.
In Java, a String is a sequence of characters. It is a built-in class in the Java language and is commonly used to represent text-based data. Strings are immutable, which means that their values cannot be changed once they are created.

Java Strings:

In Java, strings are represented by the java.lang.String class. A string is a sequence of characters and is used to represent text-based data. Strings are immutable in Java, which means that their values cannot be changed once they are created.

Initializing a String in Java:

Syntax:

String message = "Hello, world!";

Explanation:

In the above example, the String variable message is initialized with the value “Hello, world!” using string literal syntax. String literals are a sequence of characters enclosed in double quotes.
Java provides many built-in methods for working with strings, such as charAt, length, substring, toUpperCase, and toLowerCase, among others.

Some common operations that can be performed on strings in Java:

Example:

String str1 = "Hello";
String str2 = "World";
String result1 = str1 + " " + str2; // "Hello World"
String result2 = str1.concat(" ").concat(str2); // "Hello World"

Example:

String str1 = "Hello";
String str2 = "hello";
boolean result = str1.equals(str2); // false

Example:

String str = "Hello";
int length = str.length(); // 5

Example:

String str = "Hello, World!";
String result = str.substring(7, 12); // "World"

Example:

String str = "Hello, World!";
String upperCase = str.toUpperCase(); // "HELLO, WORLD!"
String lowerCase = str.toLowerCase(); // "hello, world!"

Java Program to perform Different Operations on a String:

Run
import java.util.*;

public class Main{
  public static void main(String[] args) {
    
    // Initialization of a String
    String message = "Hello, world!";
    System.out.println(message);
    
    // returning the First character of the String
    char firstChar = message.charAt(0);
    System.out.println(firstChar);
    
    // returning the length of the String
    int messageLength = message.length();
    System.out.println(messageLength);
    
    // Returns the Substring of the string
    String substring = message.substring(0, 5);
    System.out.println(substring);
    
    // converting the string to uppercase letters
    String upperCase = message.toUpperCase();
    System.out.println(upperCase);

  }
}

Output:

Hello, world!
H
13
Hello
HELLO, WORLD!

Explanation:

In this example, the charAt method is used to get the first character of the string, the length method is used to get the length of the string, the substring method is used to get a substring of the string, and the toUpperCase method is used to convert the string to uppercase.

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