Question

this is a small portion of the code:

@interface
BOOL isCarryingmallet;

@implementation

-(BOOL)isCarryingWeapon {
   return isCarryingMallet;
}

-(int)getWeaponDamage {
    if (isCarryingMallet) 
        return kVikingMalletDamage;
    else
        return kVikingFistDamage;
}

I don’t understand how this works. Does return isCarryingmMallet; return YES or NO? Why isn’t there an == YES in if (isCarryingMallet)? Why is it if (isCarryingMallet) not if (isCarryingWeapon).
Thanks for answering my newb questions!

Answer 1

The isCarryingWeapon method returns the value of the isCarryingMallet variable. If there were other possible weapons, that method could return a more complicated value, like (isCarryingMallet || isCarryingPlasmaCannon). Basically right now the only weapon that matters to this class is the mallet. When the isCarryingWeapon method is called, this class says to itself, “Am I carrying a mallet?” If so, it knows it’s carrying a weapon, so it returns true – “Yes, I’ve got a weapon.” Otherwise it returns false.

As for the if question – all if statements do is determine whether the value in the parentheses evaluates to true or false. Equality statements are pretty common in if statements but they’re not at all required. More specifically, anything that is not 0, null, or nil is true. So the following will all execute the code in the curly braces:

if (1) {...}
if (37) {...}
if (YES) {...}
if (true) {...}

Boolean variables are often named with the prefix is so that this makes natural grammatical sense. In your case, you can parse

if (isCarryingMallet) {...}

as

If this guy is carrying a mallet, then…