# C++ floor()

#### The floor() function in C++ returns the largest possible integer value which is less than or equal to the given argument.

The floor() function in C++ returns the largest possible integer value which is less than or equal to the given argument.

## floor() prototype [As of C++ 11 standard]

```double floor(double x);
float floor(float x);
long double floor(long double x);
double floor(T x); // For integral type
```

The floor() function takes a single argument and returns a value of type double, float or long double type. This function is defined in <cmath> header file.

## floor() Parameters

The floor() function takes a single argument whose floor value is computed.

## floor() Return value

The floor() function returns the largest possible integer value which is less than or equal to the given argument.

## Example 1: How floor() works in C++?

``````#include <iostream>
#include <cmath>

using namespace std;

int main()
{
double x = 10.25, result;
result = floor(x);
cout << "Floor of " << x << " = " << result << endl;

x = -34.251;
result = floor(x);
cout << "Floor of " << x << " = " << result << endl;

x = 0.71;
result = floor(x);
cout << "Floor of " << x << " = " << result << endl;

return 0;
}``````

When you run the program, the output will be:

```Floor of 10.25 = 10
Floor of -34.251 = -35
Floor of 0.71 = 0```

## Example 2: floor() function for integral types

``````#include <iostream>
#include <cmath>

using namespace std;

int main()
{
int x = 15;
double result;
result = floor(x);
cout << "Floor of " << x << " = " << result << endl;

return 0;
}
``````

When you run the program, the output will be:

```Floor of 15 = 15
```

The floor of an integral value is the integral value itself, so floor function isn't used on integral values in practice.