Two ways to construct a String/pool of strings problem

[Stanislava Trajlov]

String s1 = "Hello";
String s2 = "Hello";
String s3 = new String("Hello");
String s4 = new String ("Hello");
s1 and s2 point the same object (object A).
s3 and s4 point 2 different objects.
Does s3 point the same object as s1 and s2 (object A)?
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If the order was different:
String s3 = new String("Hello");
String s4 = new String ("Hello");
String s1 = "Hello";
String s2 = "Hello";
Again s3 and s4 point 2 different objects (object A and object B respectively).
And s1 and s2 point same string object, but which object are s1 and s2 pointing at? A or B?
Many thanks!
Stasha

[Marlene Miller]

Hi Stasha, use the equals operator == to test if two references refer to the same String object.

class Test {
   public static void main(String[] args) {
      String s1 = "Hello";
      String s2 = "Hello";
      String s3 = new String("Hello");
      String s4 = new String ("Hello");
      System.out.println(s1 == s2);  //true
      System.out.println(s3 == s4);  //false
      System.out.println(s3 == s1 | s3 == s2 | s3 == s4);  //false
      System.out.println(s4 == s1 | s4 == s2 | s4 == s3); //false
   }
}

Does s3 point the same object as s1 and s2 (object A)? No

[Marlene Miller]

class Test {
   public static void main(String[] args) {
      String s1 = "Hello";
      String s2 = new String("Hello");
      String s3 = s2.intern();
      System.out.println(s3 == s1); //true
      System.out.println(s3 == s2); //false
   }
}

String.intern() returns a String that has the same contents as the one it is invoked on.
Any two strings with the same contents return the same String object from String.intern().

[Stanislava Trajlov]

Thank You!!