Message-ID: <36FE8749.6CC4C5AC@jps.net>
Date: Sun, 28 Mar 1999 11:47:21 -0800
From: Dennis Yelle <dennis51 AT jps DOT net>
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Subject: Re: Converting between varable types
References: <7dlh6c$4b3$1 AT nnrp1 DOT dejanews DOT com>
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To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

ryan_brown AT my-dejanews DOT com wrote:
> 
> How do you convert data between variables of different types?  I need to
> convert the data in a float variable to a char variable.  In pascal you could
> just use funcitons like FloatToStr() however in c I can't find anything.  I
> have heard of casting but I can't get it to work and there isn't any
> information on it anywhere on the internet as far as I can tell.  Could
> someone point me to some source code or a function that I could use for
> converting this stuff? thanks in advance. 

There are lots of ways to do it,
but no one way is best in all cases.

Here is one way:

---------------------------- cut here ------------------------------

/* The code below was written by Dennis Yelle on March 28, 1999.
   Use it any way you like.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char *d2s( double d)
{
	char *out;
	static char buf[400];    /* 400 is probably big enough */
	
	sprintf( buf, "%g", d);  /* you might want to try %f instead of %g here
*/
	out = strdup( buf);
	if ( ! out ) {
		fprintf( stderr, "Sorry, not enough memory.\n");
		exit(9);
	}
	return out;
}

int main( int argc, char **argv)
{
	double d;
	float  f;
	int i;
	char *p;
	if ( argc < 2 ) {
		d = 9;
		for( i=0; i<310; i++) {
			d *= 10;
			p = d2s( d);
			printf( "i = %d, d = %s, ", i, p);
			free(p);
			f = d;
			p = d2s( f);
			printf( "f = %s\n", p);
			free(p);
		}
	} else {
		for( i=1; i<argc; i++) {
			d = atof( argv[i]);
			p = d2s( d);
			printf( "%s ", p);
			free(p);
		}
		printf( "\n");
	}
	return 0;
}
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