Question

I defined a NSArray in a header file like this:

@property (nonatomic, retain) NSArray *ages;

In my implementation I want to set this variable like this:

ages = [self setAges:[ageValues allKeys]];

‘ageValues’ is a NSDictionary. So what I do is just setting the array of keys to my self-defíned array. Strange enough, I get the following error message:

Asssigning to ‘NS Array *’ from incompatible type ‘void’

But where can I find something void here? In my opionion I am just setting another array ([ageValues allKeys) to my own array and I can’t find anything void???

Answer 1

The setAges: method is a method that returns void, in other words: it returns nothing (not even nil or something; it literally is not returning anything). Now you cannot assign “nothing” to a variable.

That being said, your code wants to do the same thing twice. All you want to do is simply:

self.ages = [ageValues allKeys];

or:

[self setAges:[ageValues allKeys]];

They do exactly the same, but use different syntax (the compiler transforms the first into the second).