In object-oriented programming approaches, an object is an instance of a class. The class will determine the behavior of the object, the messages (methods) it receives, and sometimes who has access to send these messages in order to obtain a response.
A class describes the properties and behaviors of a specified object, just like the blueprint of a house will describe the properties of the house, such as the number of doors in the house. Similarly, for a number, an instance of a class named
NSNumber, its class provides many ways to obtain, analyze, compare, and convert the object's internal numeric value.
Except the internal contents stored in multiple instances of a class, all the properties and actions behave identically. Check ...