# C++ <cmath> - nearbyint() Function

The C++ <cmath> nearbyint() function returns an integral value by rounding up the specified number, using the rounding direction specified by fegetround.

This function does not raise FE_INEXACT exceptions. The rint() function is similar to this function, except it may raise FE_INEXACT exceptions if the returned value differs from x.

### Syntax

```double nearbyint (double x);
float nearbyint (float x);
long double nearbyint (long double x);
double nearbyint (T x);
```

### Parameters

 `x` Specify a value to round.

### Return Value

Returns an integral value by rounding up the x, using the rounding direction specified by fegetround.

### Example:

In the example below, nearbyint() function is used to round the given number.

```#include <iostream>
#include <cfenv>
#include <cmath>
using namespace std;

void Rounding_Direction_Message(void) {
cout<<"Rounding using ";
switch(fegetround()) {
case FE_DOWNWARD:
cout<<"downward"; break;
case FE_TONEAREST:
cout<<"to-nearest"; break;
case FE_TOWARDZERO:
cout<<"toward-zero"; break;
case FE_UPWARD:
cout<<"upward"; break;
default:
cout<<"unknown";
}
cout<<" method:"<<endl;
}

int main (){
Rounding_Direction_Message();

cout<<"nearbyint(10.2): "<<nearbyint(10.2)<<"\n";
cout<<"nearbyint(10.8): "<<nearbyint(10.8)<<"\n";
cout<<"nearbyint(-5.2): "<<nearbyint(-5.2)<<"\n";
cout<<"nearbyint(-5.8): "<<nearbyint(-5.8)<<"\n";

return 0;
}
```

The output of the above code will be:

```Rounding using to-nearest method:
nearbyint(10.2): 10
nearbyint(10.8): 11
nearbyint(-5.2): -5
nearbyint(-5.8): -6
```

❮ C++ <cmath> Library

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