Java String intern() method

Java String intern() method returns canonical representation for the String Object. syntax:

public String intern()

Return: It returns a interned String that to be a pool of unique String. Java String intern() Example 1

public class JavaStringInternEx1
{ 
public static void main(String args[])
{ 
String s1=new String("Nitish");
System.out.println("String s1 : "+s1);
String s2="Nitish";
System.out.println("String s2 : "+s2);
String s3=s1.intern();//returns string from pool, now it will be same as s2 
System.out.println("Interned String is: " +s3);
System.out.println("s1 == s2---> "+(s1==s2));//false because reference variables are pointing to different instance 
System.out.println("s2 == s3---> "+(s2==s3));//true because reference variables are pointing to same instance 
}
  }

Output:

String s1 :
NitishString s2 :
NitishInterned String is: Nitishs
1 == s2---> falses
2 == s3---> true

Java String intern() Example 2

public class JavaStringInternEx2 {
    public static void main(String[] args) {
        String s1 = "TutorialAndExample.com";
        String s2 = "TutorialAndExample.com";
        String s3 = new String("TutorialAndExample.com");
        final String s4 = s3.intern();
        System.out.println("s1 == s2---> "+(s1 == s2));
        System.out.println("s2 == s3---> "+(s2 == s3));
        System.out.println("s3 == s4---> "+(s3 == s4));
        System.out.println("s1 == s3---> "+(s1 == s3));
        System.out.println("s1 == s4---> "+(s1 == s4));
        System.out.println("s1 equals s2---> "+(s1.equals(s2)));
        System.out.println("s2 equals s3---> "+(s2.equals(s3)));
        System.out.println("s3 equals s4---> "+(s3.equals(s4)));
        System.out.println("s1 equals s4---> "+(s1.equals(s4)));
        System.out.println("s1 equals s3---> "+(s1.equals(s3)));
    }
}

output:

s1 == s2---> trues
2 == s3---> falses
3 == s4---> falses
1 == s3---> falses
1 == s4---> trues
1 equals s2---> trues
2 equals s3---> trues
3 equals s4---> trues
1 equals s4---> trues
1 equals s3---> true