How to check whether a char is digit or not in Objective-C?

Question

I need to check if a char is digit or not.

NSString *strTest=@\"Test55\";
char c =[strTest characterAtIndex:4];

I need to find out if \'c\' is

Answer 1

You can think of writing a generic function like the following for this:

BOOL isNumericI(NSString *s)
{
   NSUInteger len = [s length];
   NSUInteger i;
   BOOL status = NO;

   for(i=0; i < len; i++)
   {
       unichar singlechar = [s characterAtIndex: i];
       if ( (singlechar == ' ') && (!status) )
       {
         continue;
       }
       if ( ( singlechar == '+' ||
              singlechar == '-' ) && (!status) ) { status=YES; continue; }
       if ( ( singlechar >= '0' ) &&
            ( singlechar <= '9' ) )
       {
          status = YES;
       } else {
          return NO;
       }
   }
   return (i == len) && status;
}