# Round a number to the nearest integer in C++

In this tutorial, We are going to learn about How to round off a number to the nearest integer in C++. The data types used for rounding off the integer can be are as follows:

- float
- double
- long double

Let us consider some examples to have a better understanding of the problem.

For Example: If the input is float a = 37.55555 so now the output will become result= 38

So to solve this problem we can use we can simply use a C++ STL round Function. For a detailed study about this function follow this link round() function in C++

Implementation of the Problem of rounding a number to the nearest integer

#include<iostream> #include <cmath> using namespace std; //Driver program int main() { float number ;//float datatype input double num1;// double datatype input long double num2;// long double datatype input cout<<" Enter the number "; cin>>number >> num1 >> num2 ; //printing all the rounded off number's using the C++ round STL Function cout<<" Rounded number "<<" " << round(number)<< " "<< round(num1)<<" "<< round(num2); return 0; }

OUTPUT

Enter the number 12.22 13.4559 12.19 Rounded number 12 13 12

## Round For Long Integer and Long Long Integer in C++

For rounding off of the long integer and long long integer data types we must use two more C++ STL functions which are as follows :

- llround() – For long long integer data type(Ranges from -2,147,483,648 to 2,147,483,647)
- lround() – For long integer data type(Ranges from -(2^63) to (2^63))

Below are some implementations for the following in a C++ Program

#include <cmath> #include <iostream> using namespace std; // Driver program int main() { //Below are some examples . // For lround cout << lround(-0.0) << "\n"; cout << lround(2.3) << "\n"; // For llround cout << llround(-0.01234) << "\n"; cout << llround(2.3563) << "\n"; return 0; }

OUTPUT :

0 2

0 2

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