log10, log10f, log10l

Header: <math.h>

1-3) Computes the common (base-10) logarithm of arg.

# Declarations

float log10f( float arg );

(since C99)

double log10( double arg );

long double log10l( long double arg );

(since C99)

#define log10( arg )

(since C99)

# Parameters

# Return value

If no errors occur, the common (base-10) logarithm of arg (log10(arg) or lg(arg)) is returned.

# Example

#include <errno.h>
#include <fenv.h>
#include <float.h>
#include <math.h>
#include <stdio.h>
// #pragma STDC FENV_ACCESS ON
 
int main(void)
{
    printf("log10(1000) = %f\n", log10(1000));
    printf("log10(0.001) = %f\n", log10(0.001));
    printf("base-5 logarithm of 125 = %f\n", log10(125) / log10(5));
 
    // special values
    printf("log10(1) = %f\n", log10(1));
    printf("log10(+Inf) = %f\n", log10(INFINITY));
 
    // error handling
    errno = 0; feclearexcept(FE_ALL_EXCEPT);
    printf("log10(0) = %f\n", log10(0));
    if (errno == ERANGE)
        perror("    errno == ERANGE");
    if (fetestexcept(FE_DIVBYZERO))
        puts("    FE_DIVBYZERO raised");
}

# See also