Objective-c Object

Objective-c Object Objective-c Object

• Profile
• Creating and Using objects
• News
• In-memory objects
• Id

Profile

Objects: Holds data and contains a set of functions that can use the data that the object holds. Sending a message to an object can trigger the corresponding function. This type of message-triggered function is called a method. (Data-method)

Class: Describes a specific type of object, including methods and instance variables. object to hold the data with an instance variable. An object created from a class, called an instance of that class.

Creating and Using objects

The date method of the NSDate class creates an NSDate instance, initializes it to the current date/time, and then returns the starting address of the new object.

NSDate *now = [NSDate

News

The message send (instruction) must be written in a pair of parentheses, and must contain the following two parts.

• Pointer to the object to receive the message

• Method Name, method name to trigger the method

nsdate  *now = [nsdate  Date]; nsdate  *later = [now Datebyaddingtimeinterval:100000 ]; 

• Now is the pointer to the object that receives the message, also known as the receiver (the receiver).

• Datebyaddingtimeinterval: The method name of the method to be fired, also known as the selector (the selector).

• 100000 is the passed-in argument.

In-memory objects

The pointer is in the stack, and the value of the object is in the heap.

Id

When you declare a pointer to an object without knowing the exact type of the object you are referring to, you can use the ID type, the meaning of the ID is: pointer , and you can point to any type of ojbective-c object. The ID already implies an asterisk, so you don't need an asterisk to use it.

id delegate;

Objective-c Object