Java String isEmpty Example

This Java String isEmpty example shows how to check whether the given string is empty or not using isEmpty method of Java String class.

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

  String str1 = "";
  String str2 = null;
  String str3 = "Hello World";

  /**
   * To check whether the String is empty or not, use boolean
   * isEmpty() method of Java String class.
   * 
   * This method returns true if and only if string.length() is 0.
   **/

  System.out.println("Is String 1 empty? :" + str1.isEmpty());

  // this will throw NullPointerException since str2 is null
  // System.out.println("Is String 2 empty? :" + str2.isEmpty());

  System.out.println("Is String 3 empty? :" + str3.isEmpty());

  /**
   * Please note that isEmpty method was added in JDK 1.6 and
   * it is not available in previous versions.
   * 
   * However, you can use (string.length() == 0) instead of
   * (string.isEmpty()) in previous JDK versions.
   **/
 }
}

The output is:


Is String 1 empty? :true
Is String 3 empty? :false