Example
/* ATOF.C: This program shows how numbers stored
* as strings can be converted to numeric values
* using the atof, atoi, and atol functions.
*/
#include <stdlib.h>
#include <stdio.h>
void main( void )
{
char *s; double x; int i; long l;
s = "
-2309.12E-15";
/* Test of atof */
x = atof( s );
printf( "atof test: ASCII string: %s\tfloat:
%e\n", s, x );
s = "7.8912654773d210";
/* Test of atof */
x = atof( s );
printf( "atof test: ASCII string: %s\tfloat:
%e\n", s, x );
s = "
-9885 pigs";
/* Test of atoi */
i = atoi( s );
printf( "atoi test: ASCII string: %s\t\tinteger: %d\n", s, i );
s = "98854 dollars";
/* Test of atol */
l = atol( s );
printf( "atol test: ASCII string: %s\t\tlong: %ld\n", s, l );
}
Output
atof test: ASCII string:
-2309.12E-15
float:
-2.309120e-012
atof test: ASCII string: 7.8912654773d210
float:
7.891265e+210
atoi test: ASCII string:
-9885 pigs
integer: -9885
atol test: ASCII string: 98854 dollars
long: 98854