C++ Function Overloading
Function Overloading
Function overloading allows multiple functions to have the same name, as long as their parameters are different in type or number:
Example
int myFunction(int x)
float myFunction(float x)
double myFunction(double x, double y)
float myFunction(float x)
double myFunction(double x, double y)
This lets you use the same function name for similar tasks.
Without Function Overloading
Consider the following example, which have two functions that add numbers of different type:
Example
int plusFuncInt(int x, int y) {
return x + y;
}
double plusFuncDouble(double x, double y) {
return x + y;
}
int main() {
int myNum1 = plusFuncInt(8, 5);
double myNum2 = plusFuncDouble(4.3, 6.26);
cout << "Int: " << myNum1 << "\n";
cout << "Double: " << myNum2;
return 0;
}
Try it Yourself »
return x + y;
}
double plusFuncDouble(double x, double y) {
return x + y;
}
int main() {
int myNum1 = plusFuncInt(8, 5);
double myNum2 = plusFuncDouble(4.3, 6.26);
cout << "Int: " << myNum1 << "\n";
cout << "Double: " << myNum2;
return 0;
}
Problem: We had to create two different function names for the same logic.
Using Function Overloading
Instead of defining two functions that should do the same thing, it is better to overload one.
In the example below, we overload the plusFunc function to work for both int
and double:
Example
int plusFunc(int x, int
y) {
return x + y;
}
double plusFunc(double x, double y) {
return x + y;
}
int main() {
int myNum1 = plusFunc(8, 5);
double myNum2 = plusFunc(4.3, 6.26);
cout << "Int: " << myNum1 << "\n";
cout << "Double: " << myNum2;
return 0;
}
Try it Yourself »
return x + y;
}
double plusFunc(double x, double y) {
return x + y;
}
int main() {
int myNum1 = plusFunc(8, 5);
double myNum2 = plusFunc(4.3, 6.26);
cout << "Int: " << myNum1 << "\n";
cout << "Double: " << myNum2;
return 0;
}
Note: Multiple functions can have the same name as long as the number and/or type of parameters are different.
Function Overloading by Number of Parameters
In this example, we overload a function by using a different number of parameters:
Example
int plusFunc(int x, int y) {
return x + y;
}
int plusFunc(int x, int y, int z) {
return x + y + z;
}
int main() {
int result1 = plusFunc(3, 7);
int result2 = plusFunc(1, 2, 3);
cout << "Sum of 2 numbers: " << result1 << "\n";
cout << "Sum of 3 numbers: " << result2;
return 0;
}
Try it Yourself »
return x + y;
}
int plusFunc(int x, int y, int z) {
return x + y + z;
}
int main() {
int result1 = plusFunc(3, 7);
int result2 = plusFunc(1, 2, 3);
cout << "Sum of 2 numbers: " << result1 << "\n";
cout << "Sum of 3 numbers: " << result2;
return 0;
}