Calculatrice de base en Java


J'essaie de créer un calculator de base dans Java. Je suis assez nouveau dans la programmation, donc j'essaie de m'y habituer.

import java.util.Scanner;
import javax.swing.JOptionPane;

public class javaCalculator 
{

    public static void main(String[] args) 
    {
        int num1;
        int num2;
        String operation;


        Scanner input = new Scanner(System.in);

        System.out.println("please enter the first number");
        num1 = input.nextInt();

        System.out.println("please enter the second number");
        num2 = input.nextInt();

        Scanner op = new Scanner(System.in);

        System.out.println("Please enter operation");
        operation = op.next();

        if (operation == "+");
        {
            System.out.println("your answer is" + (num1 + num2));
        }
        if  (operation == "-");
        {
            System.out.println("your answer is" + (num1 - num2));
        }

        if (operation == "/");
        {
            System.out.println("your answer is" + (num1 / num2));
        }
        if (operation == "*")
        {
            System.out.println("your answer is" + (num1 * num2));
        }


    }
}

C'est mon code. Il invite les chiffres et l'opération, mais affiche les réponses toutes ensemble ?

Author: Aruna, 2013-02-03

10 answers

Here is simple code for calculator so you can consider this
import java.util.*;
import java.util.Scanner;
public class Hello {
    public static void main(String[] args)
    {
        System.out.println("Enter first and second number:");
        Scanner inp= new Scanner(System.in);
        int num1,num2;
        num1 = inp.nextInt();
        num2 = inp.nextInt();
        int ans;
        System.out.println("Enter your selection: 1 for Addition, 2 for substraction 3 for Multiplication and 4 for division:");
        int choose;
        choose = inp.nextInt();
        switch (choose){
        case 1:
            System.out.println(add( num1,num2));
            break;
        case 2:
            System.out.println(sub( num1,num2));
            break;      
        case 3:
            System.out.println(mult( num1,num2));
            break;
        case 4:
            System.out.println(div( num1,num2));
            break;
            default:
                System.out.println("Illigal Operation");


        }



    }
    public static int add(int x, int y)
    {
        int result = x + y;
        return result;
    }
    public static int sub(int x, int y)
    {
        int result = x-y;
        return result;
    }
    public static int mult(int x, int y)
    {
        int result = x*y;
        return result;
    }
    public static int div(int x, int y)
    {
        int result = x/y;
        return result;
    }

}
 4
Author: Mohamud, 2013-09-20 08:13:32

Supprimez les deux-points de vos instructions if, sinon le code qui suit sera autonome et exécutera toujours:

if (operation == "+");
                     ^

Aussi utiliser .equals pour Strings, == compare Object références:

 if (operation.equals("+")) {
 9
Author: Reimeus, 2013-02-03 18:45:25

CompareStrings avec equals(..) pas avec ==

if (operation.equals("+")
{
    System.out.println("your answer is" + (num1 + num2));
}
if (operation.equals("-"))
{
    System.out.println("your answer is" + (num1 - num2));
}
if (operation.equals("/"))
{
    System.out.println("your answer is" + (num1 / num2));
}
if (operation .equals( "*"))
{
    System.out.println("your answer is" + (num1 * num2));
}

Et le ; après les conditions était une déclaration vide de sorte que la condition n'avait aucun effet.

Si vous utilisez java 7, vous pouvez également remplacer le si les états switch.
En java operation a une longueur 1 et que faire un commutateur pour le char [switch (operation.charAt(0))]

 3
Author: MrSmith42, 2013-02-03 18:39:12
import java.util.Scanner;
public class AdditionGame {

public static void main(String[] args) {
    // TODO Auto-generated method stub

    int num1;
    int num2;
    String operation;

    Scanner input = new Scanner(System.in);

    System.out.println("Please Enter The First Number");
    num1 = input.nextInt();

    System.out.println("Please Enter The Second Number");
    num2 = input.nextInt();

    Scanner op = new Scanner (System.in);

    System.out.println("Please Enter The Operation");
    operation = op.next();

    if (operation.equals("+"))
    {
        System.out.println("Your Answer is "+(num1 + num2));
    }
    else if (operation.equals("-"))
    {
        System.out.println("Your Answer is "+(num1 - num2));
    }       
    else if (operation.equals("*"))
    {
        System.out.println("Your Answer is "+(num1 * num2));
    }   
    else if (operation.equals("/"))
    {
        System.out.println("Your Answer is "+(num1 / num2));
    }
}

}

 0
Author: Ronak Mandania, 2013-09-11 20:31:08

Exemple de programme Java pour faire une calculatrice simple:

import java.util.Scanner;

public class Calculator
{
public static void main(String args[])
{
    float a, b, res;
    char select, ch;
    Scanner scan = new Scanner(System.in);

    do
    {
        System.out.print("(1) Addition\n");
        System.out.print("(2) Subtraction\n");
        System.out.print("(3) Multiplication\n");
        System.out.print("(4) Division\n");
        System.out.print("(5) Exit\n\n");
        System.out.print("Enter Your Choice : ");
        choice = scan.next().charAt(0);

        switch(select)
        {
            case '1' : System.out.print("Enter Two Number : ");
                a = scan.nextFloat();
                b = scan.nextFloat();
                res = a + b;
                System.out.print("Result = " + res);
                break;
            case '2' : System.out.print("Enter Two Number : ");
                a = scan.nextFloat();
                b = scan.nextFloat();
                res = a - b;
                System.out.print("Result = " + res);
                break;
            case '3' : System.out.print("Enter Two Number : ");
                a = scan.nextFloat();
                b = scan.nextFloat();
                res = a * b;
                System.out.print("Result = " + res);
                break;
            case '4' : System.out.print("Enter Two Number : ");
                a = scan.nextFloat();
                b = scan.nextFloat();
                res = a / b;
                System.out.print("Result = " + res);
                break;
            case '5' : System.exit(0);
                break;
            default : System.out.print("Wrong Choice!!!");
        }
    }while(choice != 5);       
}
}
 0
Author: Linkon, 2018-04-10 15:48:58

Peut-être que c'est mieux d'utiliser le case au lieu de if je ne sais pas si cela élimine l'erreur, mais c'est plus propre je pense.. switch (operation){case +: System.out.println("your answer is" + (num1 + num2));break;case -: System.out.println("your answer is" - (num1 - num2));break; ...

 -1
Author: Ekonion, 2013-02-03 18:37:56

Importer java.util.Scanner; import javax.swing.JOptionPane;

JavaCalculator de classe publique {

public static void main(String[] args) 
{
    int num1;
    int num2;
    String operation;


    Scanner input = new Scanner(System.in);

    System.out.println("please enter the first number");
    num1 = input.nextInt();

    System.out.println("please enter the second number");
    num2 = input.nextInt();

    Scanner op = new Scanner(System.in);

    System.out.println("Please enter operation");
    operation = op.next();

    if (operation.equals("+"))
    {
        System.out.println("your answer is" + (num1 + num2));
    }
   else if  (operation.equals("-"))
    {
        System.out.println("your answer is" + (num1 - num2));
    }

  else if (operation.equals("/"))
    {
        System.out.println("your answer is" + (num1 / num2));
    }
   else if (operation.equals("*"))
    {
        System.out.println("your answer is" + (num1 * num2));
    }
   else 
    {
       System.out.println("Wrong selection");
    }


}

}

 -1
Author: Dilip Kumar, 2013-04-10 13:30:22
public class SwitchExample {

    public static void main(String[] args) throws Exception {
        System.out.println(":::::::::::::::::::::Start:::::::::::::::::::");
        System.out.println("\n\n");

        System.out.println("1. Addition");
        System.out.println("2. Multiplication");
        System.out.println("3. Substraction");
        System.out.println("4. Division");
        System.out.println("0. Exit");
        System.out.println("\n");

        System.out.println("Enter Your Choice :::::::  ");
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String str = br.readLine();

        int usrChoice = Integer.parseInt(str);

        switch (usrChoice) {
            case 1:
                doAddition();
                break;
            case 2:
                doMultiplication();
                break;
            case 3:
                doSubstraction();
                break;
            case 4:
                doDivision();
                break;

            case 0:
                System.out.println("Thank you.....");
                break;

            default:
                System.out.println("Invalid Value");
        }

        System.out.println(":::::::::::::::::::::End:::::::::::::::::::");
}

public static void doAddition() throws Exception {
    System.out.println("******* Enter in Addition Process ********");

    String strNo1, strNo2;

    System.out.println("Enter Number 1 For Addition : ");
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    strNo1 = br.readLine();

    System.out.println("Enter Number 2 For Addition : ");
    BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in));
    strNo2 = br1.readLine();

    int no1 = Integer.parseInt(strNo1);
    int no2 = Integer.parseInt(strNo2);

    int result = no1 + no2;

    System.out.println("Addition of " + no1 + " and " + no2 + " is ::::::: " + result);
}

public static void doSubstraction() throws Exception {
    System.out.println("******* Enter in Substraction Process ********");

    String strNo1, strNo2;

    System.out.println("Enter Number 1 For Substraction : ");
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    strNo1 = br.readLine();

    System.out.println("Enter Number 2 For Substraction : ");
    BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in));
    strNo2 = br1.readLine();

    int no1 = Integer.parseInt(strNo1);
    int no2 = Integer.parseInt(strNo2);

    int result = no1 - no2;

    System.out.println("Substraction of " + no1 + " and " + no2 + " is ::::::: " + result);
}

public static void doMultiplication() throws Exception {
    System.out.println("******* Enter in Multiplication Process ********");

    String strNo1, strNo2;

    System.out.println("Enter Number 1 For Multiplication : ");
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    strNo1 = br.readLine();

    System.out.println("Enter Number 2 For Multiplication : ");
    BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in));
    strNo2 = br1.readLine();

    int no1 = Integer.parseInt(strNo1);
    int no2 = Integer.parseInt(strNo2);

    int result = no1 * no2;

    System.out.println("Multiplication of " + no1 + " and " + no2 + " is ::::::: " + result);
}

public static void doDivision() throws Exception {
    System.out.println("******* Enter in Dividion Process ********");

    String strNo1, strNo2;

    System.out.println("Enter Number 1 For Dividion : ");
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    strNo1 = br.readLine();

    System.out.println("Enter Number 2 For Dividion : ");
    BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in));
    strNo2 = br1.readLine();

    int no1 = Integer.parseInt(strNo1);
    int no2 = Integer.parseInt(strNo2);

    float result = no1 / no2;

    System.out.println("Division of " + no1 + " and " + no2 + " is ::::::: " + result);
}

}

 -1
Author: Vijay Pansheriya, 2015-10-08 12:38:02

Nous pouvons simplement utiliser dans.prochain().charAt(0); affecter + - * / les opérations de caractères par l'initialisation opération comme char.

Importer java.util.*; calculatrice de classe publique {

public static void main(String[] args) {

Scanner in = new Scanner(System.in);

char operation;
int num1;
int num2;

 System.out.println("Enter First Number");

num1 = in.nextInt();

System.out.println("Enter Operation");

operation = in.next().charAt(0);

System.out.println("Enter Second Number");

num2 = in.nextInt();

if (operation == '+')//make sure single quotes
{
    System.out.println("your answer is " + (num1 + num2));
}
if (operation == '-')
{
    System.out.println("your answer is " + (num1 - num2));
}
if (operation == '/')
{
    System.out.println("your answer is " + (num1 / num2));
}
if (operation == '*')
{
    System.out.println("your answer is " + (num1 * num2));
}

}

}

 -1
Author: ChandWeer, 2016-01-09 09:19:26
import java.util.Scanner;
public class JavaApplication1 {


    public static void main(String[] args) {

         int x,
         int y;

         Scanner input=new Scanner(System.in);
         System.out.println("Enter Number 1");
         x=input.nextInt();
         System.out.println("Enter Number 2");
         y=input.nextInt();

         System.out.println("Please enter operation + - / or *");
         Scanner op=new Scanner(System.in);
         String operation = op.next();

         if (operation.equals("+")){
             System.out.println("Your Answer: " + (x+y));
         }
         if (operation.equals("-")){
             System.out.println("Your Answer: "+ (x-y));
         }
         if (operation.equals("/")){
             System.out.println("Your Answer: "+ (x/y));
         }
         if (operation.equals("*")){
            System.out.println("Your Answer: "+ (x*y));
         }
    }

}
 -1
Author: user6153780, 2016-04-04 01:13:09