trunc(), truncf(), truncl() — Truncate an integer value

Standards

Standards / Extensions	C or C++	Dependencies
C99 Single UNIX Specification, Version 3 C++ TR1 C99	both	z/OS V1R5

Format

#define _ISOC99_SOURCE
#include <math.h>

double trunc(double x);
float truncf(float x);
long double Truncl(long double x);

C++ TR1 C99

#define _TR1_C99
#include <math.h>

float trunc(float x); 
long double trunc(long double x);

General description

The trunc functions round x to the integer value, in floating-point format, nearest to but no larger in magnitude than x.

Note: The following table shows the viable formats for these functions. See IEEE binary floating-point for more information about IEEE Binary Floating-Point.

Function	Hex	IEEE
trunc	X	X
truncf	X	X
truncl	X	X

Returned value

The trunc functions return the truncated integer value of x.

Related information

math.h