Why string == "value" returns false even if its "value"?

Question

Possible Duplicate:
How do I compare strings in Java?

User sends command "/test " to get 2 outputs: - if password was wrong - if password was correct

The correct password is "secret"

Why when user do "/test secret" it still returns that its wrong password?

@Override
    public void processCommand(ICommandSender sender, String[] args)
    {  
        if ( args.length == 1 )
        {      
            if ( args[0] != "secret" ) {
                sender.sendChatToPlayer("Wrong password " + sender.getCommandSenderName() );
            } else {
                sender.sendChatToPlayer("Welcome " + sender.getCommandSenderName() );
            }
        } else if ( args.length == 0 ) {
                sender.sendChatToPlayer("No parameters send");
        } else {
                sender.sendChatToPlayer("You have to give me just 1 argument");
        }
    }

As noted by many, many other questions on this site, this is because you need to use the `.equals()` method to compare string equality in Java. — Platinum Azure, Jan 18 '13 at 23:59
Pretty good answer to this question: http://stackoverflow.com/questions/3689952/using-instead-of-equals-for-java-strings — MatthewJ, Jan 19 '13 at 00:00
If only it was that infrequently. Can we get a close please? — , Jan 19 '13 at 00:06

score 4 · Accepted Answer · answered Jan 18 '13 at 23:59

4

Because they are different instances. Use equals() to compare strings.

answered Jan 18 '13 at 23:59

Val

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1

Exactly. `==` checks if two references refer to the same instance. – David Schwartz Jan 19 '13 at 00:00

score 0 · Answer 2 · answered Jan 19 '13 at 00:00

You should use string.equals(other_string) instead of ==, which only checks they are the same object. They may not be the same object, but may still be equal. String interning may happen in Java where the two objects are the same, but this is not guaranteed.

Why string == "value" returns false even if its "value"?

2 Answers2