Java StringBuffer Class

StringBuffer Class Introduction

The Java StringBuffer class is mutable sequence of characters. StringBuffer can be used to modify the content of a String with ease. It provides many utility functions to manipulate a string. A StringBuffer opearations are syncronized in nature and it is recommanded to be used in multi-threading environment. In case, syncronization is not needed, we can go for an alternate API StringBuffer.

StringBuffer Class Declaration

Following is the declaration for java.lang.StringBuffer class −

public final class StringBuffer
   extends Object
      implements Serializable, CharSequence

StringBuffer Class Constructors

Following is the list of constructors of the StringBuffer class.

StringBuffer Class methods

Following is the list of methods of the StringBuffer class. Each method is having multiple examples to demonstrate the functionality of the method.

Methods inherited

This class inherits methods from the following classes −

• java.lang.Object

• java.lang.CharSequence

Example: Append a Boolean to the StringBuffer

The following example shows the usage of Java StringBuffer append(Boolean b) method. Here, we are instantiating a StringBuffer object "buff" with the string name "tuts". Then, we invoke the append() method using the "buff" object with a boolean argument "true". The return value will be the appended string name "tuts true". Similarly, we demonstrate another case using the string name "abcd" and a boolean argument "false".

package com.tutorialspoint;

public class StringBufferDemo {

   public static void main(String[] args) {

      StringBuffer stringBuffer = new StringBuffer("tuts ");
      System.out.println("buffer = " + stringBuffer);

      // appends the boolean argument as string to the string stringBuffer
      stringBuffer.append(true);
      
      // print the string stringBuffer after appending
      System.out.println("After append = " + stringBuffer);

      stringBuffer = new StringBuffer("abcd ");
      System.out.println("stringBuffer = " + stringBuffer);
      
      // appends the boolean argument as string to the string stringBuffer    
      stringBuffer.append(false);
      
      // print the string stringBuffer after appending
      System.out.println("After append = " + stringBuffer);
   }
}

Output

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

buffer = tuts
After append = tuts true
stringBuffer = abcd
After append = abcd false