java println("a==b"+"is"+a==b) prints false instead of "a==b is true"

Question

Possible Duplicates:
Getting strange output when printing result of a string comparison

Hi all,

System.out.println() behaving in a different way with strings. Can any one explain why

See the below code snippet

String a ="hello"
String b ="hello"

System.out.println("a==b"+"is"+a==b)

I expect this to print 'a==b is true', but it just prints false and I dont know why.

Answer 1

A single false is printed because you didn't group your boolean expression.

The expression:

"a==b"+"is"+a==b

is evaluated as

("a==b"+"is"+a) == (b)

while you wanted it to do a string concatenation:

"a==b"+"is"+ (a==b)

That said, you shouldn't compare strings using ==, as others pointed out.