Unreachable Code Java Compilation Error

Question

I have searched many topics for my problem, read a lot... but they were not exactly as mine.

I'm getting the "Unreachable Code" compilation error from Eclipse IDE.

I don't understand why my code is unreachable! It is simple though! Here it is...

public String doAction(int action, Player P1, Player P2) {
    switch(action) {
        case 'a':
        case 'A':
            CriticalChance =  ThreadLocalRandom.current() .nextInt(CritMin,CritMax+1);
            if(CriticalChance <= 5) {
                int temp = ThreadLocalRandom.current().nextInt(31,50+1);
                P1.setAttack(temp);
            } else {
                P2.deductHp(P1.newNormalAttack());
            }

            if(CriticalChance <= 5) {
                String temp =  String.format("CRITICAL STRIKE! "+P1.getName()+" did "+P1.getAttack()+" damage to "+P2.getName()+"\n");
                return temp;
            } else {
                String temp =  String.format(P1.getName()+" did "+P1.getAttack()+" damage to "+P2.getName()+"\n");
                return temp;
            }

            if(P2.getHp() > 0) {
                String temp =  String.format(P2.getName()+"'s Remaining HP is "+P2.getHp()+"\n");
                return temp;
            } else {
                String temp =  String.format(P2.getName()+" Bled To Death!!\n");
                return temp;
            }
            break;
    }
}

Please Help! If you need more info, plz tell me.

Yep, for these types of questions, it's always best to show the error message itself, and to indicate by an obvious comment in your code, the line(s) that are causing the error. Else you force us to guess, and often we're not too good at that. — Hovercraft Full Of Eels, Oct 21 '12 at 14:35
Please add the exact error message. So that someone can point out the exact error. — saji89, Oct 21 '12 at 14:45

score 3 · Answer 1 · answered Oct 21 '12 at 14:34

3

It won't ever reach that break statement because right before it are if elses with return statements in each branch, so it'll definitely return from one of those.

answered Oct 21 '12 at 14:34

Kevin Rubin

587
8
17

score 3 · Answer 2 · answered Oct 21 '12 at 14:36

Since its returning after this:

   if(CriticalChance <= 5)
    {
        String temp =  String.format("CRITICAL STRIKE! "+P1.getName()+" did "+P1.getAttack()+" damage to "+P2.getName()+"\n");
        return temp;
    }       
    else
    {
        String temp =  String.format(P1.getName()+" did "+P1.getAttack()+" damage to "+P2.getName()+"\n");
        return temp;
    }

Any code after this is unreachable(will never be executed) since its returning in both if and else conditions. Hence compiler is complaining.

score 2 · Answer 3 · answered Oct 21 '12 at 14:37

next code is unreachable because there is no condition why code should continue after this if-else statement. The code will return a value in either case.

    if(CriticalChance <= 5)
    {
        String temp =  String.format("CRITICAL STRIKE! "+P1.getName()+" did "+P1.getAttack()+" damage to "+P2.getName()+"\n");
        return temp;
    }       
    else
    {
        String temp =  String.format(P1.getName()+" did "+P1.getAttack()+" damage to "+P2.getName()+"\n");
        return temp;
    }

the unreachable:

    if(P2.getHp() > 0)
    {
        String temp =  String.format(P2.getName()+"'s Remaining HP is "+P2.getHp()+"\n");
        return temp;
    }   
    else
    {   
        String temp =  String.format(P2.getName()+" Bled To Death!!\n");
        return temp;
    }

    break;
    }
     }}

score 2 · Answer 4 · answered Oct 21 '12 at 14:37

Look at the code starting as if(CriticalChance <= 5). Notice that the "then" and "else" both end with return statements. That means that the statement after the if is unreachable. (And you do the same thing with the next if statement too ...)

I should also point out that you are violating accepted coding standards by naming variables "CriticalChance", "CritMin" and "CritMax". A variable name should always start with a lowercase letter.

score 1 · Answer 5 · answered Oct 21 '12 at 14:35

1

It will never reach the break; statement because you are returning out of the previous if and else.

answered Oct 21 '12 at 14:35

jalynn2

6,397
2
16
15

score 1 · Answer 6 · answered Oct 21 '12 at 14:35

    if(CriticalChance <= 5)
    {
        String temp =  String.format("CRITICAL STRIKE! "+P1.getName()+" did "+P1.getAttack()+" damage to "+P2.getName()+"\n");
        return temp;
    }      
    else
    {
        String temp =  String.format(P1.getName()+" did "+P1.getAttack()+" damage to "+P2.getName()+"\n");
        return temp;
    }

below this block, your code is unreachable. Will not executed.

score 1 · Answer 7 · answered Oct 21 '12 at 14:35

1

It is because of your return temp statement as the code after this will never be executed no matter what the value of CriticalChance. The if or else, whichever condition is executed, the function will return and no more code will be executed.

answered Oct 21 '12 at 14:35

akaHuman

1,332
1
14
33

Unreachable Code Java Compilation Error

7 Answers7