用 Java 实现计算器功能

    import java.util.Scanner;
    public class Temp {        public float add(float a,float b){            return a+b;        }        public float substact(float a,float b){            return a-b;        }        public float multiply(float a,float b){            return a*b;        }        public float divide(float a,float b){            return a/b;        }        //设计一个方法  控制计算器计算的流程        public void Do() {            Scanner input = new Scanner(System.in);            System.out.println("请输入第一个数字");            String one = input.nextLine();            float a = Float.parseFloat(one);            while (true) {                System.out.println("请输入符号");                String symbol = input.nextLine();                if (symbol.equals("=")){                    System.out.println("我不玩啦，执行完毕");                    break;                }    if (!(symbol.equals("+")||symbol.equals("-")||symbol.equals("*")||symbol.equals("/"))){                    System.out.println("输入有误，符号只能是“+、-、*、/”");                    continue;                }                System.out.println("请输入第二个数字");                String tow = input.nextLine();                float b = Float.parseFloat(tow);                switch (symbol) {                    case "+":                        a = this.add(a, b);                        break;                    case "-":                        a = this.substact(a, b);                        break;                    case "*":                        a = this.multiply(a, b);                        break;                    case "/":                        a = this.divide(a, b);                        break;                }                System.out.println(a);            }        }      }