Having a little difficulty trying to figure out how to apply the check digit here. I need to be able to select a product item and check it with the "mod 10 check digit". If it fails then I need it to loop and prompt for the product number again. If zero is entered the the prog shoud terminate.
This is actually just a chunk of a project I'm working on...everything else makes sense now. Just need to be able to combine this stuff in there......
printf("\nEnter the item number (zero to quit) > ");
/*this is where I want to apply mod check*/
printf("Invalid number, please re-enter.");
If I can get the check digit in there, it will also prompt for a correct item number if alpha characters are entered, correct?