Java Boolean equality

Question

In Java Boolean.TRUE method has following implementation

 /**
 * The {@code Boolean} object corresponding to the primitive
 * value {@code true}.
 */
public static final Boolean TRUE = new Boolean(true);

and now:

System.out.println(new Boolean(true) == new Boolean(true));
System.out.println(Boolean.TRUE == Boolean.TRUE);

prints:

false
true

WHY ?!

`new Boolean(true) == new Boolean(true)` is comparing objects, not their contents. — Cardinal System, Jul 13 '17 at 15:51
https://stackoverflow.com/questions/11072870/does-check-for-full-equality-in-booleans-java — Sotirios Delimanolis, Jul 13 '17 at 15:52
@user109447 - did you try my solution? If it worked then please accept the answer and vote up! — JRG, Jul 26 '17 at 05:44

score 2 · Answer 1 · answered Jul 13 '17 at 15:56

Boolean.TRUE is not a method but a member variable declaration.

public static final Boolean TRUE = new Boolean(true);

Whenever you use new operator it creates a new instance and operator == compares instance references and not their content (equals compares contents) which means below is comparing two different instance references and not their contents, hence its false.

new Boolean(true) == new Boolean(true)

As Boolean.TRUE is static for Boolean wrapper class, below means you are comparing same static variable (not their content but actual instance reference), hence its true.

Boolean.TRUE == Boolean.TRUE

Java Boolean equality

1 Answers1