Is “new String()” immutable as well?

Question

I\'ve been studying Java String for a while. The following questions are based on the below posts

Java String is special
Immutability of String in java

Answer 1

1) Immutability: String will be immutable if you create it using new or other way for security reasons

2) Yes there will be a empty entry in the string pool.

You can better understand the concept using the code

    String s1 = new String("Test");
    String s2 = new String("Test");
    String s3 = "Test";
    String s4 = "Test";

    System.out.println(s1==s2);//false
    System.out.println(s1==s3);//false
    System.out.println(s2==s3);//false
    System.out.println(s4==s3);//true

Hope this will help your query. You can always check the source code for String class in case of better understanding Link : http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b14/java/lang/String.java