C++ Class Methods

Prerequisite: Class in C++

Class is a blueprint of an object, which has data members and member functions also known as methods. A method is a procedure or function in the oops concept. A method is a function that belongs to a class.

There are two ways to define a procedure or function that belongs to a class:

• Inside Class Definition
• Outside Class Definition

1. Inside Class Definition

The member function is defined inside the class definition it can be defined directly. Similar to accessing a data member in the class we can also access the public member functions through the class object using the dot operator (.).

Syntax:

class class_name{
public:
return_type Method_name()  // method inside class definition
{
  // body of member function
}
};

Example:

perimeter: 10
area: 6

2. Outside Class Definition

The member function is defined outside the class definition it can be defined using the scope resolution operator. Similar to accessing a data member in the class we can also access the public member functions through the class object using the dot operator (.).

Syntax:

class Class_name{

public:

return_type Method_name(); // method outside class definition

};

// Outside the Class using scope resolution operator

return_type Class_name :: Method_name() {

  // body of member function

}

Example: In the following code, a rectangle class, in which member function area() and member function perimeter() is defined outside the class by using the scope resolution operator.

perimeter: 10
area: 6