Flash cards
Review the key moves
What is the main idea behind C++ Class Methods?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
Which statement best captures the main point of this lesson?
Complete the missing token from the example code.
___ MyClass { // The classPut the learning moves in the order that makes the concept easiest to apply.
Class Methods
Methods are functions that belongs to the class.
There are two ways to define functions that belongs to a class:
- Inside class definition
- Outside class definition
Define a Method Inside the Class
In the following example, we define a function inside the class, and we name it " myMethod ".
Note
You access methods just like you access attributes; by creating an object of the class and using the dot syntax ( . ):
Inside Example
class MyClass { // The class
public: // Access specifier
void myMethod() { // Method/function
defined inside the
class
cout << "Hello World!";
}
};
int main() {
MyClass
myObj; // Create an object of MyClass
myObj.myMethod(); // Call the method
return 0;
}Define a Method Outside the Class
Sometimes it is better to declare the method in the class and define it later (especially in large programs).
This is done by specifiying the name of the class, followed the scope resolution :: operator, followed by the name of the function:
Outside Example
class MyClass { // The class
public: // Access specifier
void myMethod(); // Method/function
declaration
};
// Method/function definition outside the class void MyClass::myMethod() { cout << "Hello World!";
}
int main() {
MyClass
myObj; // Create an object of MyClass
myObj.myMethod(); // Call the method
return 0;
}Parameters
You can also pass values to methods just like regular functions:
Example
#include <iostream>
using namespace std;
class Car {
public: int speed(int maxSpeed);
};
int Car::speed(int maxSpeed) {
return maxSpeed;
}
int main() {
Car myObj; // Create an object of Car
cout << myObj.speed(200); // Call the method with an argument
return 0;
}Challenge Task
Create a class Dog with a method bark() that prints "Woof!" .
Then call that method from main() using an object of the class.
Runnable example
#include <iostream>
using namespace std;
class Dog {
public: void bark() {
cout << "Woof!";
}
};
int main() {
Dog myDog;
myDog.bark();
return 0;
}