In many supermarkets customers can pay for their shopping using credit cards. (a) Name two items of information stored on the magnetic stripe on these cards. (b) State two ways that the supermarket computer would check the credit card.

Assume a class window with accessor method getwidth that accepts no parameters and returns an integer. assume further an array of 3 window elements named winarr, has been declared and initialized. write a sequence of statements that prints out the width of the widest window in the array.