advice on why this wont run... pointers.. any advice appreciated! :)

Hi there. This program is to count the number of digits in each string. I'm really not sure if I am using pointers correctly, and not sure if i can compare them to ints like that in the if condition. Currently it wont run and gives errors:C2220: warning treated as error - no 'object' file generated, warning C4702: unreachable code

Any tips appreciated!

Code:

---

#include <stdio.h>
int count_digits(char* text);


int main(void)
{
        char* test[] =
        {
        "H3ll0", // 2 digits
        "Qu3sti0n 3...", // 3 digits
        "0ld Pr4ctic4l T3st", // 4 digits
        "is", // 0 digits
        "e4sy!" // 1 digit
        };
        for (int k = 0; k < 5; ++k)
        {
                printf("%s : ", test[k]);
                printf("%d digits\n", count_digits(test[k]));
        }
        return 0;
}


int count_digits(char* text)
{
        int count = 0;
        for (int i = 0; i < 20; i++)
        {
                if (text[i] > 47 && text[i] < 58)
                {
                        count++;
                }
        }
        return count;
        // TODO: Insert your code here...
        // TODO: Temporary stub return...
       
       
       
        return 0;
}

---

Delete the return 0; in count_digits

> for (int i = 0; i < 20; i++)
You should stop when you reach the end of the string, not keep roaming through memory.

> if (text[i] > 47 && text[i] < 58)
Saying this would be more readable.
if (text[i] >= '0' && text[i] <= '9' )

Strings are terminated with nulls in C. So to step through a string character by character, you don't stop at a set length. The most efficient way to do it is

Code:

---


int stringfunction(char *text)
{
    int i;

    for ( i = 0; text[i] != 0; i++)
    {
        /* do something with text[i] */
    }
}

---

Code:

---

int count_digits( char *s )
{
  int counter = 0;

  for (; *s; s++ )
    if ( isdigit( *s ) )
      counter++;

  return counter;
}

---

Thanks all, was the help i needed :)