C++ Class Methods

Definition: Methods are functions that are defined inside a class. They represent the "behaviors" or actions that an object can perform. While attributes store the data, methods provide the logic to manipulate or display that data.

Why: Class methods are a core part of the C++ syllabus because they implement the principle of encapsulation. By keeping functions and data together in the same block, you create self-contained objects that are easier to understand and debug.

Inside vs. Outside Definition

In C++, there are two ways to define a method belonging to a class. Both achieve the same result but are used for different levels of code organization:

Example: Implementing a Display Method

In this example, the show() method belongs to the Student class. We call it using the object s1 and the dot operator:

#include <iostream>
using namespace std;

class Student {
  public:
    // Method defined inside the class
    void show() {
        cout << "Student details displayed." << endl;
    }
};

int main() {
    Student s1; // Create object
    
    // Call the class method
    s1.show(); 
    
    return 0;
}

Key Notes

• Accessing Attributes: Methods have direct access to all attributes (variables) within the same class, even if those attributes are private.
• The this Pointer: Inside every class method, there is an implicit pointer called this which refers to the specific object that called the method.
• Parameters in Methods: Just like regular functions, class methods can accept parameters. For example: void setAge(int a) { age = a; }.
• Memory Efficiency: Even if you create 100 objects of a class, the system only stores one copy of the class methods in memory, which all objects share to save space.