用Java编写的简易计算器，可实现简易的加减乘除等运算，还可以实现撤销输入等功能。-Using Java to prepare simple calculator can achieve, such as simple addition and subtraction multiplication and division operations, but also to suspend the importation of implementation functions.

初学者的课程设计，一个简单的计算器，能计算加减乘除。(A beginner's curriculum design, a simple calculator .)