Unexpected result in String Comparison In java?

Question

public class HelloWorld {
    public static void main(String[] args) {
        String s1="yes";
        String s2="yes";

        System.out.println("-------The result is-----"+ s1==s2);
        System.out.println("-------The result is-----"+ (s1==s2));    
    }
}

Why the above code produce the output
"false"
-------The result is-----true

You'll find a lot of stuff when you google this out. If you want to compare strings, use 'equals' or 'equalsIgnoreCase' — Crickcoder, Mar 22 '14 at 08:15
possible duplicate of [How do I compare strings in Java?](http://stackoverflow.com/questions/513832/how-do-i-compare-strings-in-java) — Rakesh KR, Mar 22 '14 at 08:18

score 5 · Answer 1 · answered Mar 22 '14 at 08:15

First of all, you should not be comparing strings with ==, but with equals().

There's also the issue of operator precedence. This:

"-------The result is-----"+ s1==s2

is the same as:

("-------The result is-----"+ s1) == s2

because + has higher precedence than ==.

score 0 · Answer 2 · answered Mar 22 '14 at 08:15

when you are comparing strings you should change up == to be .equals() due to the fact that .equals() compares the contents of the strings to each other or is used to compare objects. == checks for reference equality or is used to compare primitives. I changed your code below:

System.out.println("-------The result is-----"+ (s1.equals(s2)));

score 0 · Answer 3 · answered Mar 22 '14 at 08:15

0

You are comparing the references of s1 and s2, and since you defined them separately, they don't have the same references. To compare the strings, please use equals or equalsIgnoreCase

answered Mar 22 '14 at 08:15

anirudh

4,116
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score 0 · Answer 4 · answered Mar 22 '14 at 08:15

0

'+' > '=='

so

"-------The result is-----"+ s1==s2 becomes

("-------The result is-----"+ s1)==s2 and hence false.

answered Mar 22 '14 at 08:15

RKC

1,834
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Unexpected result in String Comparison In java?

4 Answers4