
答案(这里面包括main方法不要写重了),copy即可使用:
public static void main(String[] args) { while (true){ System.out.println("请输入您要选择的符号(+,-,*,/)输入x退出计算机:"); Scanner scanner = new Scanner(System.in); String v = scanner.next(); if (v.equals("x")){ System.out.println("您已经退出计算机系统"); break; }else if (v.equals("+")){ System.out.println("请输入您要计算的数字两位数字"); }else if (v.equals("-")){ System.out.println("请输入您要计算的数字两位数字"); }else if (v.equals("*")) { System.out.println("请输入您要计算的数字两位数字"); }else if (v.equals("/")) { System.out.println("请输入您要计算的数字两位数字"); }else { System.out.println("输入错误字符,自动退出计算机"); break; } System.out.print("请输入第一个数字:"); Scanner scanner1 = new Scanner(System.in); double num1 = scanner1.nextDouble(); System.out.print("请输入第二个数字:"); Scanner scanner2 = new Scanner(System.in); double num2 = scanner2.nextDouble(); //switch只能用做String或者char double result=0; switch (v){ case "+": result=add(num1,num2); break; case "-": result=subtraction(num1,num2); break; case "*": result=ride(num1,num2); break; case "/": result=divide(num1,num2); break; default: System.out.println("输入错误自动退出"); break; } System.out.println("您的答案是:"+result); }}public static double add(double num1,double num2){ return num1+num2;}public static double subtraction(double num1,double num2){ return num1-num2;}public static double ride(double num1,double num2){ return num1*num2;}public static double divide(double num1,double num2){ return num1/num2;}