Question

I created a custom object in Objective-C. Now I want to create a custom initializer. The object has two properties, name and score. So my initializer is as follows:

- (id)initWithName:(NSString *)playerName {

    if ((self = [super init])) {
        self.name = [playerName retain];
        self.score = [NSNumber numberWithInt:0];
    }

    return self;
}

Am I using retain here properly? Or can I just make it something like self.name = playerName;?

Furthermore, assume I want another initializer, but keep the initWithName:playerName the designated initializer. How would I make the second initializer call the first?

And for the last question, I know I need to override the - (id)init method too. However, what do I do there? Just assign test properties incase the class was initialized with init only?

Thank you!

Answer 1

Am I using retain here properly?

No you are not. You should either use

self.name = playerName;

as you suggested, or (as recommended by Apple)

name = [playerName copy];

It is not recommended to use accessors in -init because subclasses might override them.

Also, note that as NSString implements NSCopying you should use a copy property, not a retain property.

Furthermore, assume I want another initializer, but keep the initWithName:playerName the designated initializer. How would I make the second initializer call the first?

Using -init as an example (because you must override the super class’s designated initialiser if your designated initialiser is not the same)

-(id) init
{
    return [self initWithName: @"Some default value"];
}