What is a receiver in Objective C?

Question

I'm confused as to what a 'receiver' is in Objective-C?

On the follwing site is says the following about what a receiver is: https://quizlet.com/104540068/objective-c-flash-cards/

"In Objective-C, you specify the object (known as the receiver of the method) and the message being sent to that object by enclosing the message expression in brackets."

I don't understand this. I'm very new to Objective C. Any help is appreciated. Thanks.

Answer 1

In Objective-C, a message is sent to a receiver.

The message is the method you are calling. The receiver is the what the message is called on.

Example. Let's say you have an NSString:

NSString *str = @"Hello";

Now you want to get the length of the string. You send the length message to str. str is the receiver of the message:

NSInteger len = [str length];

Basically, the receiver is the part on the left inside the square brackets and the message is the part on the right in the square brackets.