Java.lang.StringBuilder.setCharAt() Method

Description

The java.lang.StringBuilder.setCharAt() method sets the character at the specified index to ch.The index argument must be greater than or equal to 0, and less than the length of this sequence.

Declaration

Following is the declaration for java.lang.StringBuilder.setCharAt() method

public void setCharAt(int index, char ch)

Parameters

• index -- This is the index of the character to modify.

• ch -- This is the new character.

Return Value

This method does not return any value.

Exception

• IndexOutOfBoundsException -- if index is negative or greater than or equal to length().

Example

The following example shows the usage of java.lang.StringBuilder.setCharAt() method.

package com.tutorialspoint;

import java.lang.*;

public class StringBuilderDemo {

  public static void main(String[] args) {
  
    StringBuilder str = new StringBuilder("AMIT");
    System.out.println("string = " + str);
    // character at index 3
    System.out.println("character at index 3 = " + str.charAt(3));
  
    // set character at index 3
    str.setCharAt(3, 'L');
  
    System.out.println("After Set, string = " + str);
    // character at index 3
    System.out.println("character at index 3 = " + str.charAt(3));
  }
}

Let us compile and run the above program, this will produce the following result:

string = AMIT
character at index 3 = T
After Set, string = AMIL
character at index 3 = L