@property and @synthesize in objective-c

Question

While I was playing and figure out how things work in https://github.com/enormego/EGOTableViewPullRefresh I found mysterious of @property and @synthesize. Here is the code I

Answer 1

You are right, using

@synthesize foobar=_foobar;

is a bit pointless in most cases , but at an abstract level it does allow you to return the value of some other variable entirely. As in ...

@synthesize foobar=fluffybunny;

Lets you get or set the value of fluffybunny each time you use the accessor .foobar

However in terms of the@synthesize complexity , would you rather write

-(void)setFoobar:(id)aobject {
    [self willSetValueForKey:"foobar"];
    id old = foobar;
    foobar = [aobject retain];
    [old release];
    [self didSetValueForKey:"foobar"];
}

-(id)foobar {
    [self willAccessValueForKey:"foobar"];
    id obj = [self primitiveValueForKey:@"foobar"];
    [self didAccessValueForKey:"foobar"];    
    return obj;
}

Or

@synthesize foobar;

Thats not particularly well written as ive forgotten how to do them well but the @synthesize directive stops you having to write accessors so many times. It one one of the things that sucked heavily about Obj-C 1.0.

Free code , dont knock it.