Methods, Messages, and Selectors

In standard C, you’d perform two function calls to allocate and initialize data. Here is how that might look, in contrast to Objective-C’s [[Car alloc] init] statement:

Car *myCar = malloc(sizeof(Car));
init(myCar);

Objective-C doesn’t use function_name(arguments) syntax. Instead, you send messages to objects using square brackets. Messages tell the object to perform a method. It is the object’s responsibility to implement that method and produce a result. The first item within the brackets is the receiver of the message; the second item is a method name, and possibly some arguments to that method that together define the message you want sent. In C, you might write

printCarInfo(myCar);

but in Objective-C, you say: