Function Call Operator Overloading in C++
How to overload function call operator in C++?
The operator “()” is known as function call operator. When a function call operator is overloaded it does not modify how functions are called but, it modifies how the operator is to be explained when passed through objects of a given type.
Function call operator overloading is a sub part of operator overloading in C++. On this page, we will learn more about function call operator overloading in C++. But if you want to know more about operator overloading click the button below.
Function call operator overloading in C++
- Function call operator is overloaded by instance of the class and it is also known as function object.
- When we overload function call operator, we are not creating a new way to call a function. But, we are creating an operator function that can be passed a number of parameters.
- It only modifies how the operator is to be fetched by the object.
Syntax for function call operator overloading in C++
class class_name
{
public:
void operator ()();
}; 
Program to overload function call operator in C++
#include <iostream>
using namespace std;
class Length
{
private:
int kmeter;
int meter;
public:
Length()//Constructor.
{
kmeter = 0;
meter = 0;
}
Length(int km, int m)
{
kmeter = km;
meter = m;
}
Length operator()(int x, int y, int z)//Overload function call operator.
{
Length l;
l.kmeter = x + z + 10;
l.meter = y + z + 100 ;
return l;
}
//Method to display length.
void disLength() {
cout << kmeter <<"Km " << meter << "M" << endl;
}
};
int main()
{
Length l1(1, 112), l2;
cout << "First length: ";
l1.disLength();
l2 = l1(6, 7, 8); //Invoking function call operator.
cout << "Second length:";
l2.disLength();
return 0;
}Output:
First length: 1Km 112M Second length:24Km 115M
Prime Course Trailer
Related Banners
Get PrepInsta Prime & get Access to all 200+ courses offered by PrepInsta in One Subscription
Get over 200+ course One Subscription
Courses like AI/ML, Cloud Computing, Ethical Hacking, C, C++, Java, Python, DSA (All Languages), Competitive Coding (All Languages), TCS, Infosys, Wipro, Amazon, DBMS, SQL and others
Login/Signup to comment