Examples to compare strings in Java?

== compares Object reference

.equals() compares String value

Sometimes == gives illusions of comparing String values, in following cases

String a="Test";
String b="Test";
if(a==b) ===> true

This is a because when you create any String literal, JVM first searches for that literal in String pool, if it matches, same reference will be given to that new String, because of this we are getting

(a==b) ===> true

                       String Pool
     b -----------------> "test" <-----------------a

== fails in following case

String a="test";
String b=new String("test");
if (a==b) ===> false

in this case for new String("test") the statement new String will be created in heap that reference will be given to b, so b will be given reference in heap not in String Pool. Now a is pointing to String in String pool while b is pointing to String in heap, because of that we are getting

if(a==b) ===> false.

                String Pool
     "test" <-------------------- a

                   Heap
     "test" <-------------------- b

While .equals() always compares value of String so it gives true in both cases

String a="Test";
String b="Test";
if(a.equals(b)) ===> true

String a="test";
String b=new String("test");
if(a.equals(b)) ===> true

So using .equals() is awalys better.

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