c - Loop with simple counter malfunctioning? -

i have program takes char array , calls function convert. function determines whether character letter or number. program supposed output first letter finds in string. , first numbers finds in string. loop stop looking letters after finds 1 isn't working.

any thoughts? code written in c using borland compiler.

#include <stdio.h> #include <math.h> #include <stdlib.h> #include <ctype.h> #include <string.h>  int convert (char array[],char **);  int main() {     int intval;      char array[512], *charptr;      printf("input string starts series of decimal digits:\n>");     while ( gets( array ) != null ){         intval = convert(array, &charptr );         printf ("intval contains %d, charptr contains '%s'\n", intval, charptr);     }     system("pause");      return 0;   } int convert (char array[],char ** charptr) {     int i, x, c = 0;     char b[512];     (i=0;i<strlen(array);i++){          if (isalpha(array[i]))         {             if(c >= 1){                  *charptr = &array[i];                 c++;                 }             else                  break;           }         else if ( isdigit(array[i]))                 x = 10*x + array[i] - '0';       }      return  x; } 

update:

#include <stdio.h> #include <math.h> #include <stdlib.h> #include <ctype.h> #include <string.h>   int convert (char array[],char ** charptr);    int main() {     int intval;      char array[512], *charptr;      printf("input string starts series of decimal digits:\n>");     while ( gets( array ) != null ){         intval = convert(array, &charptr );         printf ("intval contains %d, charptr contains '%s'\n", intval, charptr);     }     system("pause");      return 0;   } int convert (char array[],char ** charptr) {     int i, x, c;     char b[512];    (i=0;array[i] != 0;i++){         if ( isdigit(array[i]))                  x = 10*x + array[i] - '0';         else if (isalpha(array[i]))         {             c++;             if(c >= 1){                  *charptr = &array[i];              }           }      }      return  x; } 

you have logic error. c initialized 0. there line increment c inside if block never true.

        if(c >= 1){              *charptr = &array[i];             c++;             } 

catch 22???

perhaps meant use:

int convert (char array[],char ** charptr) {     int i, x, c = 0;     char b[512];     (i=0;i<strlen(array);i++){          if (isalpha(array[i]))         {                 // no need checking value of c                 // return find alphabet.                 *charptr = &array[i];                 break;             }         else if ( isdigit(array[i]))                 // if looking alphabet only,                 // why have block of code???                 x = 10*x + array[i] - '0';     }      return  x; } 

update

perhaps, looking for.

int convert (char array[], char ** charptr) {    size_t i;    int x = 0;    size_t len = strlen(array);     // set charptr null in case there no letters in input.    *charptr = null;    (i=0;i<len;i++){        if ( isalpha(array[i]))       {          *charptr = &array[i];          return x;       }       else if ( isdigit(array[i]))       {          x = 10*x + array[i] - '0';       }    }     return x; }