CODEWITHSUNDEEP
javafor-loopswitch-statement
user1486147
user1486147

Reputation:

Switch statement not being entered

I'm experiencing a strange problem. I have a case statement, and it is not being entered, at all. I've stepped it through with the Eclipse debugger and it gets the line above and then goes straight to the line after. It compiles and runs with no errors.

This is a general outline:

    for (int k = 0; k<9; k++) {
        System.out.println("Program is here - #1");
        doSomething();
        switch (switchcode) {

        case 1:
            switch (k) {

            case 1: case 2: case 3:
                doOneOneTwoThree(); //#2
                break;
            case 4: case 5: case 6:
                doOneFourFiveSix(); //#3
                break;
            default:
                System.err.println("error k defaulted in case 1");
                break;
            }
            break;
        case 2:
            switch (k) {

            case 1: case 2: case 3:
                doTwoOneTwoThree(); //#4
                break;
            case 4: case 5: case 6:
                doTwoFourFiveSix(); //#5
                break;
            default:
                System.err.println("error k defaulted in case 2");
                break;
            }
            break;
        default:
            System.err.println("error switchcode defaulted");
            break;
        }

        doSomethingElse();
    }

I'm doing something wrong, no doubt, but I really don't know what exactly. Is it because I am switching on k within a case? I have done this before and it has worked, perhaps luckily.

Is the nesting of case statements within a larger for-loop causing problems?

I saw "Branch Prediction Fail" occasionally whilst I was researching around, I don't know exactly what that is but it might be happening.

Is having break; in the default cases causing problems? I don't think it is because I tried it without them and had the same results.

Sorry for the long code and question. Thanks for ANY guidance.

Upvotes: 2

Views: 1683

Answers (2)

Peter Lawrey
Peter Lawrey

Reputation: 533520

The most likely explanation is that you are not debugging the compiled code you think you are. What you can see when you are running slightly old classes with new source is that the source will be correct and up to date, but the compiled code will skip to old line numbers which can look sort of right.

I would try to do as clean a build as you can. If that doesn't work try moving the code around. e.g. adding lots of blank lines.

Upvotes: 2

Puce
Puce

Reputation: 38132

If Eclipse doesn't hit a line it should, then the source might be out-of-sync with the code compiled by Eclipse.

Try to do a clean & new build.

Restarting Eclipse or reimporting the project might also help.

Upvotes: 4

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