# trunc() function with example in C++

C++ trunc() function: Here, we are going to learn about the trunc() function with example of cmath header in C++ programming language?
Submitted by IncludeHelp, on April 27, 2019

## C++ trunc() function

trunc() function is a library function of cmath header, it is used to round (truncate) the value toward zero, it accepts a number and returns the nearest integral value that is not the larger in magnitude than the given number.

## Syntax

Syntax of trunc() function:

```trunc(x);
```

## Parameter(s)

x – is the number to round toward zero.

## Return value

double – it returns double type value that is the rounded (truncated) value of the number x.

## Sample Input and Output

```Input:
float x = 2.3;
Function call:
trunc(x);
Output:
2

Input:
float x = 2.8;
Function call:
trunc(x);
Output:
2
```

## Example

```// C++ code to demonstrate the example of
// trunc() function

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

// main() section
int main()
{
float x;

//input the number
cout<<"Enter a float value: ";
cin>>x;

//rounding doward zero
cout<<"trunc("<<x<<"): "<<trunc(x);
cout<<endl;

return 0;
}
```

### Output

```First run:
Enter a float value: 2.3
trunc(2.3): 2

Second run:
Enter a float value: 2.5
trunc(2.5): 2

Third run:
Enter a float value: 2.8
trunc(2.8): 2

Fourth run:
Enter a float value: -2.3
trunc(-2.3): -2

Fifth run:
Enter a float value: -2.5
trunc(-2.5): -2

Sixth run:
Enter a float value: -2.8
trunc(-2.8): -2
```