Simple code implementation of addition, subtraction, multiplication and division calculator

Addition, subtraction, multiplication and division calculator simple code implementation

Thinking is introduced ： Use circulation and Switch Make selection operator , Compiling .

Code example

package method;
import java.util.Scanner;
public class Demo06 {
    
    public static void main(String[] args) {
    
            double result=0;
            Scanner scanner = new Scanner(System.in);
            while (true){
    
                System.out.print(" Please enter the first number to be calculated ：");
                double first = scanner.nextDouble();
                System.out.print(" Please enter the operator to evaluate ：");
                String fuhao = scanner.next();
                System.out.print(" Please enter the second number to be calculated ：");
                double second = scanner.nextDouble();
                switch (fuhao){
    
                    case "+":
                        result=first + second;
                        System.out.println(" The result is ："+result);
                        continue;
                    case "-":
                        result=first - second;
                        System.out.println(" The result is ："+result);
                        continue;
                    case "*":
                        result=first * second;
                        System.out.println(" The result is ："+result);
                        continue;
                    case "/":
                        result=first / second;
                        System.out.println(" The result is ："+result);
                        continue;
                    default:
                        System.out.println(" Please enter the correct operation symbol ！！！！");
                }
            }
    }
}

Console display

D:\apps\jdk8\bin\java.exe "-javaagent:E:\javanote\IntelliJ IDEA Community Edition 2021.1\lib\idea_rt.jar=63184:E:\javanote\IntelliJ IDEA Community Edition 2021.1\bin" -Dfile.encoding=UTF-8 -classpath D:\apps\jdk8\jre\lib\charsets.jar;D:\apps\jdk8\jre\lib\deploy.jar;D:\apps\jdk8\jre\lib\ext\access-bridge-64.jar;D:\apps\jdk8\jre\lib\ext\cldrdata.jar;D:\apps\jdk8\jre\lib\ext\dnsns.jar;D:\apps\jdk8\jre\lib\ext\jaccess.jar;D:\apps\jdk8\jre\lib\ext\jfxrt.jar;D:\apps\jdk8\jre\lib\ext\localedata.jar;D:\apps\jdk8\jre\lib\ext\nashorn.jar;D:\apps\jdk8\jre\lib\ext\sunec.jar;D:\apps\jdk8\jre\lib\ext\sunjce_provider.jar;D:\apps\jdk8\jre\lib\ext\sunmscapi.jar;D:\apps\jdk8\jre\lib\ext\sunpkcs11.jar;D:\apps\jdk8\jre\lib\ext\zipfs.jar;D:\apps\jdk8\jre\lib\javaws.jar;D:\apps\jdk8\jre\lib\jce.jar;D:\apps\jdk8\jre\lib\jfr.jar;D:\apps\jdk8\jre\lib\jfxswt.jar;D:\apps\jdk8\jre\lib\jsse.jar;D:\apps\jdk8\jre\lib\management-agent.jar;D:\apps\jdk8\jre\lib\plugin.jar;D:\apps\jdk8\jre\lib\resources.jar;D:\apps\jdk8\jre\lib\rt.jar;E:\javanote\out\production\Hello method.Demo06
 Please enter the first number to be calculated ：5
 Please enter the operator to evaluate ：/
 Please enter the second number to be calculated ：5
 The result is ：1.0
 Please enter the first number to be calculated ：5
 Please enter the operator to evaluate ：+
 Please enter the second number to be calculated ：5
 The result is ：10.0
 Please enter the first number to be calculated ：5
 Please enter the operator to evaluate ：-
 Please enter the second number to be calculated ：5
 The result is ：0.0
 Please enter the first number to be calculated ：5
 Please enter the operator to evaluate ：*
 Please enter the second number to be calculated ：5
 The result is ：25.0
 Please enter the first number to be calculated ：5
 Please enter the operator to evaluate ：5
 Please enter the second number to be calculated ：5
 Please enter the correct operation symbol ！！！！
 Please enter the first number to be calculated ：