[Java] Missing Return Statement

[Lapje]

Hi guys, I was wondering why this method:

public DisplayMode findFirstCompatibleMode(DisplayMode modes[]){
        DisplayMode goodModes[] = vc.getDisplayModes();
        for(int x = 0; x < modes.length; x++){
            for(int y = 0; y < goodModes.length; y++){
                if(displayModesMatch(modes[x], goodModes[y])){
                    return modes[x];
                }
            }
        }
    }

says: 'Missing Return Statement'

It clearly says 'return modes[x]' right .

vc is my Graphics Device btw.

 

[holthelper]

im not a java person but i think its because its looking for a return in case the code comes out false

 

[NemesisToKill]

im not a java person but i think its because its looking for a return in case the code comes out false

Yup, look at your code in the for loop, the return statement is within an if statement. What if that if statement turns out to be false? Then it can't return anything as there is no other code to be read.

It should be

public DisplayMode findFirstCompatibleMode(DisplayMode modes[]){
        DisplayMode goodModes[] = vc.getDisplayModes();
        for(int x = 0; x < modes.length; x++){
            for(int y = 0; y < goodModes.length; y++){
                if(displayModesMatch(modes[x], goodModes[y])){
                    return modes[x];
                }
            }
        }
return null;
    }

 

[Negata]

The above is correct. To be precise, if modes.length is 0, even the outermost loop won't be entered.

 

[jM2.me]

Wouldn't you have to break loop after finding first mode?

 

[Team Lion]

No, return will redirect program flow out of the loop and back to the caller. I use it extensively, for example:

double eval(ArrayList<Double> in) {
			switch(this) {
				case ADD:
					return in.get(1) + in.get(0);
				case SUB:
					return in.get(1) - in.get(0);
				case MUL:
					return in.get(1) * in.get(0);
				case DIV:
					return in.get(1) / in.get(0);
				case MOD:
					return in.get(1) % in.get(0);
				case POW:
					return Math.pow(in.get(1), in.get(0));
				case SQRT:
					return Math.sqrt(in.get(0));	
				case ABS:
					return Math.abs(in.get(0));
				case TOBOOL:
					return (in.get(0) > 0) ? 1.0 : 0.0;
				default:
					throw new ArithmeticException("Floating point inputs can only be operated on by floating point operators!");				
			}
		}

 

[Lapje]

Kk thanks guys, I'll try it in a minute =]
--------
Works guys, thanks a million.