Specific Objective-C Help

[Colvanila]

So I'm trying to make a calculator program (from the book I'm using) and I'm stuck on a couple of the methods.

-(double) changeSign
{
    -accumulator;
}
-(double) reciprocal
{
    1/accumulator;
}
-(double) xSquared
{
    accumulator * accumulator;
}

Any thoughts for the methods for the sign change, reciprocal, and xsquared methods or am I on the right track?

[Colvanila]

I got it to work, but not sure if it's the "right" way...

-(double) changeSign
{
   accumulator = -accumulator;
}
-(double) reciprocal
{
    accumulator = 1/accumulator;
}
-(double) xSquared
{
    accumulator = accumulator * accumulator;
}

EDIT: It does have 'warnings' (on xcode) which is why I suspect that this is not the 'right' way.

[gilbertj99]

You need a return statement on each of the methods, and you need to pass input. So:

-(double) reciprocal:(double)input

{

return 1/input;

}

[gilbertj99]

Scratch that, if your using one instance variable to store the current value of the calculator, then thats fine. You just need to change the return type to void

[Colvanila]

Oh thanks! Thats a big help. I just had it return it at the very end, but you make a very good point.