StringBuilder reverse() in Java with Examples

The reverse() method of StringBuilder is used to reverse the characters in the StringBuilder. The method helps to this character sequence to be replaced by the reverse of the sequence. Syntax:

public java.lang.AbstractStringBuilder reverse()

Returns: This method returns StringBuilder object after reversing the characters. Below programs illustrate the java.lang.StringBuilder.reverse() method: Example 1:

Java

// Java program to demonstrate
// the reverse() Method.

class GFG {
    public static void main(String[] args)
    {

        // create a StringBuilder object
        // with a String pass as parameter
        StringBuilder str
            = new StringBuilder("WelcomeGeeks");

        // print string
        System.out.println("String = "
                           + str.toString());

        // reverse the string
        StringBuilder reverseStr = str.reverse();

        // print string
        System.out.println("Reverse String = "
                           + reverseStr.toString());
    }
}

Output:

String = WelcomeGeeks
Reverse String = skeeGemocleW

Example 2:

Java

// Java program to demonstrate
// the reverse() Method.

class GFG {
    public static void main(String[] args)
    {

        // create a StringBuilder object
        // with a String pass as parameter
        StringBuilder str
            = new StringBuilder("AAAABBBCCCC");

        // print string
        System.out.println("String = "
                           + str.toString());

        // reverse the string
        StringBuilder reverseStr = str.reverse();

        // print string
        System.out.println("Reverse String = "
                           + reverseStr.toString());
    }
}

Output:

String = AAAABBBCCCC
Reverse String = CCCCBBBAAAA

References: https://docs.oracle.com/javase/10/docs/api/java/lang/StringBuilder.html#reverse()