C++ trunc() function usage and examples

C++ Library Function <cmath>

trunc() prototype [from C ++ 11[Standard]

double trunc(double x);
float trunc(float x);
long double trunc(long double x);
double trunc(T x);　//integer type

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

trunc() parameter

The trunc() function takes a single parameter, whose trunc value will be calculated.

trunc() return value

In short, the trunc() function truncates the decimal part and returns only the integer part.

Example1: How does trunc() work in C ++working in C?

#include <iostream>
#include <cmath>
　
using　namespace　std;
　
int　main()
{
　　　　double x =　10.25, result;
　　　　result　=　trunc(x);
　　　　cout　<<　"trunc("　<<　x　<<　")　=　"　<<　result　<<　endl;
　
　　　　x =　-34.251;
　　　　result　=　trunc(x);
　　　　cout　<<　"trunc("　<<　x　<<　")　=　"　<<　result　<<　endl;
　
　　　　return　0;
}

When the program is executed, the output is:

trunc(10.25)　=　10
trunc(-34.251)　=　-34

Example2: The trunc() function of integer type

#include <iostream>
#include <cmath>
using　namespace　std;
int　main()
{
　　　　int　x　=　15;
　　　　double　result;
　　　　result　=　trunc(x);
　　　　cout　<<　"trunc("　<<　x　<<　")　=　"　<<　result　<<　endl;
　　　　return　0;
}

When the program is executed, the output is:

trunc(15)　=　15

For integer values, the trunc function will return the same result. Therefore, it is not commonly used to represent integer values in practice.

C++ Library Function <cmath>