Java.lang.StringBuilder.append() Method



The java.lang.StringBuilder.append(CharSequence s, int start, int end) method appends a subsequence of the specified CharSequence to this sequence.

Characters of the argument s, starting at index start, are appended, in order, to the contents of this sequence up to the (exclusive) index end. The length of this sequence is increased by the value of end - star.


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

public StringBuilder append(CharSequence s, int start, int end)


  • s − This is the sequence to append.

  • start − This is the starting index of the subsequence to be appended.

  • end − This is the end index of the subsequence to be appended.

Return Value

This method returns a reference to this object.


IndexOutOfBoundsException − if start or end are negative, or start is greater than end or end is greater than s.length()


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

package com.tutorialspoint;

import java.lang.*;

public class StringBuilderDemo {

   public static void main(String[] args) {
      StringBuilder str = new StringBuilder("tutorials ");
      System.out.println("string = " + str);

      CharSequence cSeq = "tutspoint";
      // appends the CharSequence with start index 4 and end index 9
      str.append(cSeq, 4, 9);
      // print the StringBuilder after appending
      System.out.println("After append = " + str);

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

string = tutorials
After append = tutorials point