How to write my own setter for an ivar, i.e.: self.ivar = …?

Question

This is a follow-up question of: Difference between self.ivar and ivar? :

self.name = @\"hello\";

I would like to know what is done inside

Answer 1

Without a property declaration (that is, you have manually declared the setter and getter methods), you'd typically implement them like this:

@interface MyClass : NSObject
{
    NSString *name;
}
- (NSString *) name;
- (void) setName:(NSString *) name;
@end

@implementation MyClass

- (void) dealloc
{
    [name release];
    [super dealloc];
}

- (NSString *) name
{
    return name;
}

- (void) setName:(NSString *) aName
{
    if (aName != name)
    {
        [name release];
        name = [aName retain];
    }
}

@end

Atomic setters could look something like this:

- (void) setName:(NSString *) aName
{
    @synchronized(self)
    {
        if (aName != name)
        {
            [name release];
            name = [aName retain];
        }
    }
}