this point is especially true when class may have many different users typicallya class can be used over and over by different users (or the same userfor different purposes for examplesomeone might use the lowarray class in some other program to store the serial numbers of his traveler' checks the class can handle this task just as well as it can store the numbers of baseball players if class is used by many different programmersthe class should be designed so that it' easy to use the way that class user relates to the class is called the class interface because class fields are typically privatewhen we talk about the interfacewe usually mean the class methods--what they do and what their arguments are by calling these methodsa class user interacts with an object of the class one of the important advantages conferred by object-oriented programming is that class interface can be designed to be as convenient and efficient as possible figure is fanciful interpretation of the lowarray interface private data lem ete (te ge lem lowarra interface figure the lowarray interface not so convenient the interface to the lowarray class in lowarray java is not particularly convenient the methods setelem(and getelem(operate on low conceptual levelperforming exactly the same tasks as the [operator in an ordinary java array the class userrepresented by the main(method in the lowarrayapp classends up having to carry out the same low-level operations it did in the non-class version of an array in the