Which is not necessary when using bar codes in supermarkets? A. Point-of sale (POS) terminal B. Check digit on the bar code C. Price on the shelf D. Price on the goods E. None of the above
Price on the shelf is not necessary when using bar codes in supermarkets. It also contains a check digit, so that the computer can validate that the data has been read in correctly. The barcode does not contain price. The price is held in the database instead. This makes it easy to change if there are special offers or prices go up.
