Why Don't These Strings Match?

Question

I'm getting the user input like so:

Scanner keyboard = new Scanner(System.in);
String input = keyboard.nextLine();

When I compare it like this

if(input == "abc"){
  System.out.println("Match!");
}else{
  System.out.println(input + "\nabc");
}

If I type "abc" I see

abc
abc

Instead of the expected match. What's going on?

I'd say that's a dupe. I'm learning Java; moving from JavaScript -- That's a new concept to me. — Gary, Jan 20 '14 at 01:44
This question is not dumb. Every rookie makes this mistake. No worries. — Pshemo, Jan 20 '14 at 01:48
To add onto what @Pshemo said, most beginners make the mistake that Strings in Java are treated as primitives. This is due to the way they are initialized and how operators affect them. I know I was there at one point too. — Obicere, Jan 20 '14 at 01:52

score 3 · Accepted Answer · answered Jan 20 '14 at 01:44

3

You are comparing String references, not String values. Use the String.equals method instead.

answered Jan 20 '14 at 01:44

Ned

score 1 · Answer 2 · answered Jan 20 '14 at 01:43

1

== is comparing memory locations. you need to use input.equals("abc") instead.

answered Jan 20 '14 at 01:43

axiopisty

2 Answers2