[Reading Notes] iOS-strong and weak types, Reading Notes ios-type

[Reading Notes] iOS-strong and weak types, Reading Notes ios-type

Id is a common type. OC uses id to represent any type of objects. It can be used as a placeholder to indicate that this is an uncertain type object or reference. Therefore, all objects can be represented by IDs. This is very useful. Imagine that if you need to implement a common linked list class, you can declare the data field type in the linked list node as the id type, then you can store any type of objects in this linked list.

 

 

References: iOS programming guide