Thread: help

This is a simple atol function that i've defined
it works for 1, 2, 4, 6, 7 digit numbers. but not 3, 5, 8, 9, and 10 digit numbers.
it puzzling me, can somebody help me out?

Code:

long atol (const char * nptr)
{
char temp [SIZE];

int i=0;
int j=0;
int sum =0;
initialize (temp);

while (isdigit(nptr[i]))
{
i++;
}

if ( i == 0 )
	{
	return sum=-99;
	}

else
{
	while (j < i)
	{
	sum = sum + ((nptr[j]-48) * (pow(10,(i-j-1))));
	j++;
	}
return sum;
}

[code][/code]tagged by Salem

thx a lot salem!
rounding errors? u circumvent it by substracting it by '0' instead of 48 izzit?

Originally posted by kulshaker
This is a simple atol function that i've defined

Simple, but not quite. This is simple :

Code:

#include <stdio.h>
#include <ctype.h>

unsigned long ConvStr(char* lpsz)
{
	char *temp = lpsz;
	unsigned long result = *temp - '0';
	while(*(++temp) != '\0' && isdigit(*temp) )
	{
		result = result * 10 + (*temp - '0');
	}
	return result;
}

int main()
{
	char *lpsz = "1234a56789";
	unsigned long num;

	num = ConvStr(lpsz);

	printf("%lu", num);

	return 0;
}