nearbyint() function in C++

The nearbyint() function is defined in cmath header file. This function round off the given value to a nearby integral value by using the current rounding method. The current rounding method is described by fegetround.

Syntax:

float nearbyint(float x);

or,
double nearbyint(double x);

or,
long double nearbyint(long double x);

Parameters: This function accepts single parameter x which contains floating point value.

Return Value: It returns the rounded value of x to a nearby integral value by using the rounding method. 

Time Complexity: O(1)
Auxiliary Space: O(1)

Below programs illustrate the nearbyint() function in C++:

Program 1:

CPP

// C++ program to demonstrate
// example of nearbyint() function.

#include <bits/stdc++.h>
using namespace std;
int main()
{
    float x = 2.7;

    cout << "Value of x = " << x << endl;
    cout << "Round off value of x = " << nearbyint(x);

    return 0;
}

Output

Value of x = 2.7
Round off value of x = 3

Program 2:

CPP

// C++ program to demonstrate
// example of nearbyint() function.

#include <bits/stdc++.h>
using namespace std;
int main()
{
    double x = 3.2;

    cout << "Value of x = " << x << endl;
    cout << "Round off value of x = " << nearbyint(x);

    return 0;
}

Output

Value of x = 3.2
Round off value of x = 3