8. Write a function that takes in a string parameter and checks to see whether or not it is an integer, and if it is then return the integer value.

8. Write a function that takes in a string parameter and checks to see whether or not it is an integer, and if it is then return the integer value.

#include <stdio.h>

 int strtoint(char *s)

{

 int index = 0, flag = 0;

while( *(s+index) != '\0')

{ 

if( (*(s + index) >= '0') &&  *(s + index) <= '9')

{

 flag = 1; index++;

}

 else

{

 flag = 0;

 break;

}

}

if( flag == 1 ) return atoi(s);

else return 0;

}

 main() 

{

  printf("%d",strtoint("0123"));  printf("\n%d",strtoint("0123ii"));  

}