Calculatrice de base en Java

Je suis en train de créer une base de calculator dans Java. Je suis assez nouveau dans la programmation, donc je suis à essayer de s'habituer à elle.

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 demande le nombre et le fonctionnement, mais affiche toutes les réponses ensemble ?

Est-ce la programmation des devoirs? C'est un très commun de première année de la tâche dans CS.
essayez Entier.parseInt(num1) + Integer.parseInt(num2); et de supprimer des points virgule (;) si l'instruction !
oui je suis à la lecture de l'informatique, première année 🙂

OriginalL'auteur user2037720 | 2013-02-03

  1. 5
    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;
}
}
    Alors que ce code techniquement fonctionne, il le fait par l'exploitation de façon différente le code de la question, d'une manière qui évite d'aborder des bogues dans le code.

    OriginalL'auteur Mohamud

  2. 10

    Enlever le point-virgule à partir de votre if états, sinon le code qui suit sera debout libre et sera toujours exécuté:

    if (operation == "+");
^

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

     if (operation.equals("+")) {
    ^ Ce. Putain vous par le chemin. D'être un programmeur débutant moi-même, je pensais enfin être en mesure de répondre à une question! Hélas, pas assez rapide!!
    ThankYouu, sur place! 🙂

    OriginalL'auteur Reimeus

  3. 3

    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 la ; après les conditions était une déclaration vide de sorte que la condition n'a eu aucun effet du tout.

    Si vous utilisez java 7, vous pouvez également remplacer le si les états switch.

    En java <7, vous pouvez tester, si operation est de longueur 1 et de faire un interrupteur pour la char [switch (operation.charAt(0))]

    OriginalL'auteur MrSmith42

  4. 0
    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));
}
}

    }

    Répondre s'il vous plaît essayez d'ajouter un peu de texte naturel pour expliquer votre solution, au moins un peu.

    OriginalL'auteur Ronak Mandania

  5. 0

    Programme Java exemple pour faire une simple Calculatrice:

    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);       
}
}

    OriginalL'auteur Linkon

  6. -1

    peut-être de son mieux à l'aide de la case au lieu de if ne sais pas si cela élimine l'erreur, mais son 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; ...

    OriginalL'auteur Ekonion

  7. -1

    importer 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.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");
}
}

    }

    OriginalL'auteur Dilip Kumar

  8. -1
    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);
}

    }

    OriginalL'auteur Vijay Pansheriya

  9. -1

    nous pouvons simplement utiliser .next().charAt(0); à attribuer + - * / opérations de caractères par l'initialisation de la opération comme un char.

    importer java.util.*;
    public class Calculatrice {

    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));
}
}

    }

    OriginalL'auteur ChandWeer

  10. -1
    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));
}
}
}
    Pas voté, mais vous devriez ajouter l'explication plutôt que seulement le code de réponse

    OriginalL'auteur user6153780