# fdim() function with example in C++

C++ fdim() function: Here, we are going to learn about the fdim() function with example of cmath header in C++ programming language.
Submitted by IncludeHelp, on April 26, 2019

## C++ fdim() function

fdim() function is a library function of cmath header, it is used to find the positive difference between two numbers, it accepts two numbers and returns their positive difference.

Syntax of fdim() function:

```    fdim(x, y);
```

Parameter(s): x, y – are the numbers whose positive difference to be calculated.

Return value: double – it returns double value that is the positive difference of the numbers x and y.

Example:

```    Input:
float x = 20;
float y = 10;

Function call:
fdim(x,y);

Output:
10
```

### C++ code to demonstrate the example of fdim() function

```// C++ code to demonstrate the example of
// fdim() function
#include <iostream>
#include <cmath>
using namespace std;

// main() section
int main()
{
float x;
float y;
float result;

//input the numbers
cout<<"Enter first number : ";
cin>>x;
cout<<"Enter second number: ";
cin>>y;

//finding the positive difference
result = fdim(x,y);
cout<<"fdim("<<x<<","<<y<<"): "<<result;
cout<<endl;

return 0;
}
```

Output

```First run:
Enter first number : 10
Enter second number: 20
fdim(10,20): 0

Second run:
Enter first number : 20
Enter second number: 10
fdim(20,10): 10

Third run:
Enter first number : -10.1234
Enter second number: -20.1231
fdim(-10.1234,-20.1231): 9.9997

Fourth run:
Enter first number : -20.1231
Enter second number: -10.1234
fdim(-20.1231,-10.1234): 0
```