Incrementing int in Java within a loop

Question

I've searched all over in the last couple hours and I just can't get a simple counter going in Java! I tried AtomicInteger and it's getAndIncrement() method but that didn't work.

Basically I have a for loop, and within that an if statement, I want an int to be incremented by 1 everytime in the for loop the if statement equates to true. And then after the for loop, return the int.

The int doesn't increment.

Help!

Edit - It's on Eclipse for Android:

public int markTest(Map<Long, String> selectedAnswers,
            Map<Long, String> correctAnswers) {
        int mark = 0;
        for (long i = 1; i <= selectedAnswers.size(); i++) {

            String userSelection = selectedAnswers.get(i).toString();
            if (userSelection == correctAnswers.get(i))
                mark++;
        }

        return mark;
    }

`intValue++`? I think your question might be missing some context — MadProgrammer, Jun 26 '13 at 00:46
If you post what you have so far, it would be easier for someone to help you — morgano, Jun 26 '13 at 00:46
I'll change that, however the if is definitely equating to true for the moment as I used Log.i - but the mark++ isn't doing its job — Omair Vaiyani, Jun 26 '13 at 00:54
Because that's not how you compare strings, so `mark` is never incremented. Possible duplicate of [How do I compare strings in Java?](http://stackoverflow.com/questions/513832/how-do-i-compare-strings-in-java) — Brian Roach, Jun 26 '13 at 01:02
@OmairVaiyani I know you mean that you're sure both the values are same but trust us when we say `==` would still fail you there. — Ravi K Thapliyal, Jun 26 '13 at 01:02

score 2 · Accepted Answer · edited May 23 '17 at 11:44

The correct way to check string equality is to use String.equals() instead of equality == operator.

if (userSelection.equals(correctAnswers.get(i))) {

Since, your if condition is failing all the time mark is not getting incremented. Also, there's no need for toString() since selectedAnswers is already of type Map<Long, String>

String userSelection = selectedAnswers.get(i);

References:
Java String.equals versus ==
How do I compare strings in Java?

score 0 · Answer 2 · answered Jun 26 '13 at 00:51

0

after the if statement write count++ example and don't forget to initialize the count outside the loop count=0 or what ever number you want to start with.

if(condition) count++;

return count;

answered Jun 26 '13 at 00:51

Ivan_Stepul

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Incrementing int in Java within a loop

2 Answers2