In C++, stream insertion operator “<<” is used for output and extraction operator “>>” is used for input.
We must know following things before we start overloading these operators.
1) cout is an object of ostream class and cin is an object istream class
2) These operators must be overloaded as a global function. And if we want to allow them to access private data members of class, we must make them friend.
Why these operators must be overloaded as global?
In operator overloading, if an operator is overloaded as member, then it must be a member of the object on left side of the operator. For example, consider the statement “ob1 + ob2” (let ob1 and ob2 be objects of two different classes). To make this statement compile, we must overload ‘+’ in class of ‘ob1’ or make ‘+’ a global function.
The operators ‘<<' and '>>' are called like 'cout << ob1' and 'cin >> ob1'. So if we want to make them a member method, then they must be made members of ostream and istream classes, which is not a good option most of the time. Therefore, these operators are overloaded as global functions with two parameters, cout and object of user defined class.
Following is complete C++ program to demonstrate overloading of <> operators.
Enter Real Part 10 Enter Imagenory Part 20 The complex object is 10+i20
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above
- Function Overloading in C++
- Operator Overloading in C++
- Constructor Overloading in C++
- Function Overloading and float in C++
- Rules for operator overloading
- Does overloading work with Inheritance?
- Overloading New and Delete operator in c++
- C++ | Operator Overloading | Question 10
- Types of Operator Overloading in C++
- Increment (++) and Decrement (--) operator overloading in C++
- Function overloading and return type
- Function overloading and const keyword
- C++ program to compare two Strings using Operator Overloading
- Overloading Subscript or array index operator  in C++
- C++ Program to concatenate two strings using Operator Overloading