C++ How to Program, 10/e

14.7 Random-Access Files

So far, we’ve seen how to create sequential files and search them to locate information. Sequential files are inappropriate for instant-access applications, in which a particular record must be located immediately. Common instant-access applications are airline reservation systems, banking systems, point-of-sale systems, automated teller machines and other kinds of transaction-processing systems that require rapid access to specific data. A bank might have hundreds of thousands (or even millions) of other customers, yet, when a customer uses an automated teller machine, the program checks that customer’s almost instantly for sufficient funds. This kind of instant access is made possible with random-access files. Individual ...