What's wrong with == operator on java string

Question

I have,
String str1 = "StringA";
String str2 = "StringA";

Now, I do

(str1 == str2)

Sometimes it doesn't match the strings and returns false

But str1.equals(str2) always returns true

What I'm missing here?
I cannot always use equals as my String can be null also.

Thanks!

This is Java 101 and is covered in the FAQ section of [this site's Java tag](http://stackoverflow.com/tags/java/info). — Marko Topolnik, May 09 '13 at 13:03
@MarounMaroun That's the *lower bound* on the number of such questions :) — Marko Topolnik, May 09 '13 at 13:04

PSR · Accepted Answer · 2013-05-09T13:11:26.870

3

== compares references not the content

To compare strings you need to use String#equals:

.equals(); //If you  consider the case
.equalsIgnoreCase(); //If you not consider the case

edited May 09 '13 at 13:11

answered May 09 '13 at 13:02

PSR

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score 1 · Answer 2 · edited May 23 '17 at 12:13

1

== compares the exact values. So it compares if the primitive values are the same,

.equals() calls the comparison method of objects, which will compare the actual objects pointed by the references. In the case of Strings, it compares each character to see if they're equal.

Read more here :

Why doesn’t == work on String?

edited May 23 '17 at 12:13

Community

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answered May 09 '13 at 13:03

Suresh Atta

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@Downvoter can you please explain what's wrong with my lines ? – Suresh Atta May 09 '13 at 13:04

What's wrong with == operator on java string

2 Answers2