I need help with looping

I wrote this to covert the string to double, but I'm having problem fixing the loop so that it goes through all the digits. when I run this it only converts the first which is -42.40000 and stops.

Code:

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#include<stdio.h>
#include<stdlib.h>
#include<ctype.h>
main(){
      double result, convert(char s[]);
      char arr[]="-42.4 5 34 66";
      result=convert(arr);
      printf("%f", result);
      getchar();
      }
     
double convert(char s[])
      {
      double val, power;
      int i, sign,pos,c;
      for (i =0; isspace(s[i]); i++) ;
      sign = (s[i] == '-') ? -1 : 1;
      if (s[i] == '+' || s[i] == '-')
      i++;
      for (val = 0.0; isdigit(s[i]); i++)
      val = 10.0 * val + (s[i] - '0');
      if (s[i] == '.')
      i++;
      for (power = 1.0; isdigit(s[i]); i++)
          {
            val = 10.0 * val + (s[i] - '0');
            power *= 10;
          }
return sign * val / power;

}

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Yes, because you only call the "convert" function once, and convert itself converts only the first float in the string.

You have two choices - either iterate over the strings in the main (skip to the next space each time you have converted a number), or build a list of double's in the convert functions. The lattter is probably best done by passing an array and array-size into the function and returning a count of how many you actually got converted.



I would put braces around the "decimal" handling part, so that the for-loop to deal with the decimals is inside the if checking for a '.' in the string.

--
Mats

I'm a kinda finding figuring out how to implement what you said.

Quote:

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Originally Posted by matsp

I would put braces around the "decimal" handling part, so that the for-loop to deal with the decimals is inside the if checking for a '.' in the string.

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This isn't necessary (like indentation isn't necessary hah, makes thing clearer tough). I'm sure you can easily figure why. ;)

But since i'm already writing things down, this is some kind of proof i'm posting for fun:

Code:

---

double convert(char s[])
      {
      double val, power;
      int i, sign,pos,c;
      for (i =0; isspace(s[i]); i++) ;
      sign = (s[i] == '-') ? -1 : 1;
      if (s[i] == '+' || s[i] == '-')
              i++;
      for (val = 0.0; isdigit(s[i]); i++)
              val = 10.0 * val + (s[i] - '0');

      /* A: s[i] isn't a digit */

      if (s[i] == '.')
      {
              i++;
              /* A: s[i] is something haha */
      }

      else
      {
              /* A: s[i] isn't a digit, that means the condition in the for loop will be false on the first iteration */
      }

      for (power = 1.0; isdigit(s[i]); i++)
          {
            val = 10.0 * val + (s[i] - '0');
            power *= 10;
          }
return sign * val / power;

}

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