objective c help - calling methods?

Hey, I am new to programming I wanted to know why is it always [self method];? I mean why is it that way could someone explain me why is it self and what is going on in the background? sorry if 开发者_C百科it is a stupid question

thanks, TC

Basically, what self refers to is the object that you're currently in the context of. [self somemethod] means that you're invoking a method named somemethod in the class that self was initialized as.

For example, if you were to do something like this:

Foo *f = [[Foo alloc]init];
[f someMethod];

You'd be invoking someMethod on the Foo instance.

But if you're working inside of the class Foo, self serves as an explicit reference to the current object. In this case, you'd simply use [self someMethod] to invoke someMethod.

-(id) init {
    if (self = [super init]) {
        [self someMethod];
    }
    ...
}

-(void) someMethod { }

Does that help?

1. [self method] calls the method of the calling class. For example, in the header file of your class,

   @interface YourClass : NSObject {

   }

   - (void) myMethod;

then, you can call the 'myMethod' in YourClass by using [self myMethod]. Does it make sense?

1. During calling [self method], there is no any background working. [self method] is almost same the calling function in C. When you use [self method], 'method' in your class is just called right away.

Because [self method]; calls the -method method in the class from which it is called.

If you want kill John in ObjC:

[john sendBullet]

if you do sendBullet to myself (shortly self), it's a suicide

[self sendBullet]

got the difference? :)