Question

In my program i want to input a string of integer e.g 2107900000. I want to get its length and then want to remove all the 0’s and 1’s.

Answer 1

Perhaps not optimal, but you could copy it into another buffer conditionally:

 char buffer[20];
 char num[] = "2107900000";
 int j = 0;
 for (int i = 0; num[i]; i++)
 {
   if (num[i] != '0' && num[i] != '1')
   {
     buffer[j] = num[i];
     j++;
   }
 }
 buffer[j] = 0 //null terminator

Or you could do it in a single buffer:

 char num[] = "2107900000";
 int j = 0;
 for (int i = 0; num[i]; i++)
 {
   if (num[i] != '0' && num[i] != '1')
   {
     num[j] = num[i];
     j++;
   }
 }
 num[j] = 0 //null terminator