With function overloading, we can create multiple functions with the same name. This may be achieved with one of the below cases:

* Different number of arguments 
* Different types of arguments

# Different number of arguments 

A function can be overloaded by having a different number of arguments for each function with the same name.

```
// same name diffenrent number of arguments 
int add(int a, int b);
int add(int a, int b, int c);
```

In the code above, we created two functions with the same name, but each function has a different number of arguments.

#include <iostream>
using namespace std;

int add(int a, int b){
  return a + b;
}

int add(int a, int b, int c){
  return a + b + c;
}

int main() {
  
  cout << "calling add with three arguments: " << add(10, 20, 30) << endl;
  cout << "calling add with two arguments: " << add(10, 20) << endl;
  
  return 0;
}

# Different types of arguments 

A function can be overloaded by having different types of arguments for each function with the same name.

```
// same name diffenrent argument types
int absolute(int a);
int absolute(float a);
```

In the code above, we created two functions with the same name, but each function has a different type of argument.

#include <iostream>
using namespace std;

int absolute(int a){
  return a < 0 ? -a : a;
}

int absolute(float a){
  return a < 0.0 ? -a : a;
}

int main() {
  
  cout << "calling absolute with float value : " << absolute(-1.3f) << endl;
  cout << "calling absolute with int value: " << absolute(-10) << endl;
  
  return 0;
}

---
> The overloaded function can have different return types.

# Invalid function overloading

## Only changing return type

We cannot achieve function overloading by only changing the return type.

```
// this will throw compile time error 
int test();
float test();
```

The above code will throw a compile-time error because the compiler gets ambiguity on which `test` method should be called. 

---

## Default value in function 

```
// ambiguity error 
int add(int a)
int add(int a, int b = 10);

add(4);
```

In the code above, we have added the default value for the second `add` function. By compiling the compiler, we will get ambiguity on which add method should be executed upon calling `add` with a single argument.

What is function overloading in C++?

With function overloading, we can create multiple functions with the same name. This may be achieved with one of the below cases:  Different number of arguments Different types of arguments  Different number of arguments A function can be overloaded by having a different number of arguments for each function with the same name. // same name diffenrent number of arguments  int add(int a, int b); int add(int a, int b, int c);  In the code above, we created two functions with the same name, but each function has a different number of arguments. 