Class Methods in C++
Class methods are functions that are defined inside a class to perform some operation on the data member of the class.
A class method can be defined in two ways:
- Inside the class definition
- Outside the class definition
Defining Method inside the Class
In the example below, we created a class Product and defined a method getPrice() inside the class:
#include <iostream>
using namespace std;
class Product
{
public:
double getPrice()
{ // This is the method
return 700.56;
}
};
// creating an object of the class
int main()
{
Product product; // we create an object myobject
double price = product.getPrice(); // calling the method
cout<<"Product Price is : "<< price;
return 0;
}
Output
Product Price is : 700.56
Outside the class definition
Here, we define a method inside the class first and then define the same method outside the class. For that, we give the name of the class, followed by the operator :: then followed by the name of the method.
In the example below, we created a class Transaction and defined a method getAmount() outside the class.
#include <iostream>
using namespace std;
class Transaction
{
private:
double amount = 0;
public:
void setAmount(double amount);
double getAmount();
};
//first method outsite class
void Transaction::setAmount(double amount)
{
this->amount = amount;
}
// second method outside class
double Transaction::getAmount()
{
return this->amount;
}
// creating an object of the class
int main()
{
Transaction transaction; // creating an object
transaction.setAmount(240); // setting amount
double amount = transaction.getAmount(); // getting amount
cout << "The transaction amount is : " << amount;
return 0;
}
Output
The transaction amount is : 240