利用java来实现计算器的加减乘除

package bag;

import java.util.Scanner;

public class Demo06 {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

System.out.println("请输入要操作的选项：1 加法 2 减法 3 乘法 4 除法");

String str = sc.next();

char select=str.charAt(0);

switch (select) {

case '1':

System.out.println("请输入第一个数：");

double a = sc.nextDouble();

System.out.println("请输入第二个数：");

double b = sc.nextDouble();

double sum = add(a, b);

System.out.println("两个数的和为:" + sum);

break;

case '2':

System.out.println("请输入被减数：");

double c = sc.nextDouble();

System.out.println("请输入减数：");

double d = sc.nextDouble();

double difference = subtract(c, d);

System.out.println("两个数的差为:" + difference);

break;

case '3':

System.out.println("请输入第一个数：");

double e = sc.nextDouble();

System.out.println("请输入第二个数：");

double f = sc.nextDouble();

double ride = multiply(e, f);

System.out.println("两个数的积为:" + ride);

break;

case '4':

System.out.println("请输入被除数：");

double g = sc.nextDouble();

System.out.println("请输入除数：");

double h = sc.nextDouble();

double except = divide(g, h);

System.out.println("两个数的商为:" + except);

break;

default:

System.out.println("你的输入有误，请重新输入：");

break;

}

}

public static double add(double a,double b){

return a + b;

}

public static double subtract(double a,double b){

return a - b;

}

public static double multiply(double a,double b){

return a * b;

}

public static double divide(double a,double b){

return a / b;

}

}