An Overview of Function Overloading in C++

Function overloading is the process of having two or more functions with the same names but different parameters. It enables one to use the same name for different functions in the same class. Some rules must be considered when overloading a function.

Function Overloading Rules

More like this:

• C++ Passing Function Arguments and Returning Values
• C++ Variables and Data Types
• C++ Recursion

Ways to Overload a Function in C++

There are various ways of overloading a function. They include,

Contrasting number of arguments

Two functions are defined using the same names but different parameters of the same type. For instance, a sum() function can illustrate the concept of overloading by having two definitions, one that accepts three arguments and another that accepts four arguments. An illustration is shown below.

Function 1

int main()
int sum(int a, int b, int c) {
  cout << a + b + c;
}

Function 2

int sum(int a, int b, int c, int d) {
  cout << a + b + c + d;
}

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Separate types of arguments

Multiple functions are defined using the same name and number of parameters. However, the type of parameters used is different. Below is an illustration that uses the sum() function, one that obtains integer arguments and obtains double arguments.

#include<iostream>
#include<conio.h>

// Function 1
int sum(int a, int b) {
  cout << a + b;
}

// Function 2
double sum(double a, double b) {
  cout << a + b;
}

int main() {
  sum(50, 70)
  sum(50.5, 70.5)
}

Constructor Overloading in C++

A constructor is considered to be special due to the following reasons.

Operator Overloading

Operators are overloaded to carry out special operations about the classes created. They can be overloaded by creating operator functions. By using the keyword operator, an operator function is created. Operator functions often return objects of the class they operate on.

Restrictions to operator overloading

Over-loadable operators

+ - * / % ^

& | ~ ! , =

< > <= >= ++ --

<< >> == != && ||

+= -= /= %= ^= &=

|= *= <<= >>= []

-> ->* new new [] delete delete []

[adinserter block=”2″]

Non-overloadable operators

:: .* . ?:

Operator overloading syntax

Returntype classname::operator operatorsymbol(argument list) {
  Statement(s);
}

Rules regarding operator overloading