Understanding and application of the class in program design

By programming we mean a process in which program design language is adopted to produce a system that computers can recognize.There are various methods in programing with the development of the computer science. However,in the past,the frequently-adopted method is the process-oriented design,while nowadays the most frequently-adopted one is object-oriented design,in which the most essential element is class.This paper gives an understanding and some applications of class.