The **nanf() function** is used to get the `NaN` (not a number) value of the type float. 

It accepts an argument that is basically a string, then returns the `NaN` value of type `float.`

# Standard library
```c
#include<cmath>
```

# Syntax
```c
float nanf (const char* str);
```

# Parameters
`str` - a string value

# Return value

It returns a `NaN` value which is in float.

# Code


#include <iostream>
#include <cmath>
using namespace std;
int main()
{
    float nanValue;
    //generating generic NaN value by passing an empty string
    nanValue = nanf("");
    cout << "nanValue: " << nanValue << endl;

    return 0;
}

What is nanf() in C/C++?

The nanf() function returns a NaN value of type float and receives a string argument.