What is floorf() in C?

floorf() in C is used to calculate the largest integer value not greater than the argument value. floorf() is defined in the math.h header file and the function declaration is as follows:

float floorf(float arg);

Parameters and return value

arg: floating point value

Return value: largest integer value not greater than arg

Example program

#include <math.h>                                                               
#include <stdio.h>                                                              
                                                                                
int main(void)                                                                  
{  
    printf("floor(+3.0) = %.1f\n", floorf(3.0));                                                                             
    printf("floor(+3.9) = %.1f\n", floorf(3.9));
    printf("floor(-3.9) = %.1f\n", floorf(-3.9));
    printf("floor(-0.0) = %.1f\n", floorf(-0.0));
    printf("floor(0.0) = %.1f\n", floorf(0.0));
    /* special cases */
    printf("floor(inf) = %.1f\n", floorf(INFINITY));
    printf("floor(-inf) = %.1f\n", floorf(-INFINITY));
    printf("floorf = %f\n", floorf(NAN)); 
    return 0;                                          
}

Explanation

First, we import the math.h header file from the C standard library. The program then simply prints the output of floorf() on possible example values.

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