Editing Function overloading (section)

==Rules in function overloading==
* The same function name is used for more than one function definition in a particular module, class or namespace
* The functions must have different [[type signature]]s, i.e. differ in the number or the types of their formal parameters (as in C++) or additionally in their return type (as in Ada).<ref>{{cite book
| last1 = Watt
| first1 = David A.
| last2 = Findlay
| first2 = William
| title = Programming Language Design Concepts
| date = 1 May 2004
| publisher = John Wiley & Sons, Inc.
| isbn = 978-0-470-85320-7
| pages = 204–207
}} 
</ref>

Function overloading is usually associated with [[statically-typed]] programming languages that enforce [[type checking]] in [[function call]]s. An overloaded function is a set of different functions that are callable with the same name. For any particular call, the compiler determines which overloaded function to use and resolves this at [[compile time]]. This is true for programming languages such as Java.{{sfn|Bloch|2018|loc=§Chapter 8 Item 52: Use overloading judiciously|p=238-244}}

Function overloading differs from forms of [[Polymorphism (computer science)|polymorphism]] where the choice is made at runtime, e.g. through [[virtual function]]s, instead of statically.

'''Example: Function overloading in C++'''
<syntaxhighlight lang=Cpp>
#include <iostream>

int Volume(int s) {  // Volume of a cube.
  return s * s * s;
}

double Volume(double r, int h) {  // Volume of a cylinder.
  return 3.1415926 * r * r * static_cast<double>(h);
}

long Volume(long l, int b, int h) {  // Volume of a cuboid.
  return l * b * h;
}

int main() {
  std::cout << Volume(10);
  std::cout << Volume(2.5, 8);
  std::cout << Volume(100l, 75, 15);
}
</syntaxhighlight>

In the above example, the volume of each component is calculated using one of the three functions named "volume", with selection based on the differing number and type of actual parameters.