program review

[shuaib.akram]

hi
is there any better method for finding sum of three numbers??

#include<stdio.h>
main()
{
int a,s;
printf("enter a number");
scanf("%d",&a);
for( ;a!=0;)
{
s=s+(a%10);
a=a/10;
}
printf("the sum is%d",s);
getch();
}

[robatino]

You mean the sum of the digits? No, not really. Since this code won't work properly with negative numbers, you should make a and s an unsigned int (use %u instead of %d). You should also write "int main()" instead of "main()" since C99 will require explicit return types. You could also write "s += a%10;" and "a /= 10;".

Edit: Better yet, "int main(void)". You could also replace "for( ;a!=0;)" with the clearer "while (a != 0)" or just "while (a)".

[brewbuck]

hi
is there any better method for finding sum of three numbers??

Since you are processing the number digit-by-digit anyway, there's no much point in converting it to a real integer at all:

int main()
{
    char number[16], *ptr;
    int sum = 0;

    scanf("%15s", number);
    for(ptr = number; *ptr; ptr++)
    {
        sum += *ptr - '0';
    }
    printf("The sum is %d", sum);
    return 0;
}

[MacNilly]

No, that's not the best way.

Try learning some math, like some "Sum of" algorithms.