Console calculator

Core exercise

A calculator that chains operations until the user chooses 0. Stick to the signatures below: the checks rely on them.

Goals: Menus, switch, loops, splitting into methods.

Features

• Menu: 1) Addition 2) Soustraction 3) Multiplication 4) Division 0) Quitter (keep these French labels, the checks look for them).
• Reading two numbers (double) and printing the result.
• A loop that chains operations until 0 (quit).
• Handling division by zero: an error message (containing “Erreur”), not a crash.

Steps

1. afficherMenu() → prints the options.
2. lireChoix(Scanner sc) → returns an int between 0 and 4.
3. lireOperande(Scanner sc, String nom) → returns a double.
4. One method per operation: addition(a, b), soustraction(a, b), multiplication(a, b), division(a, b).
5. boucleCalculatrice(Scanner sc) → orchestrates the whole thing with a do…while.

Criteria: No crash, error cases handled, code split into clear methods.

A workshop goes here: you write and run code in it. It requires JavaScript.

Starting code

Calculatrice.java

import java.util.Scanner;

public class Calculatrice {

    public static void afficherMenu() {
        // TODO : afficher les 5 options
    }

    public static int lireChoix(Scanner sc) {
        // TODO : lire un entier entre 0 et 4
        return 0;
    }

    public static double lireOperande(Scanner sc, String nom) {
        // TODO : demander puis lire un double
        return 0;
    }

    public static double addition(double a, double b) {
        return 0;
    }

    public static double soustraction(double a, double b) {
        return 0;
    }

    public static double multiplication(double a, double b) {
        return 0;
    }

    public static double division(double a, double b) {
        return 0;
    }

    public static void boucleCalculatrice(Scanner sc) {
        // TODO : do { menu, choix, operandes, resultat } while (choix != 0);
    }
}

Exercices.java

import java.util.Scanner;

public class Exercices {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Calculatrice.boucleCalculatrice(sc);
        sc.close();
    }
}

The core exercise is validated in the workshop, which requires JavaScript.

Hint 1

Division by zero on doubles does not throw an exception: it gives Infinity. It is up to you to test b == 0 before dividing.

Extensions

• History of calculations (via ArrayList<String>).
• Scientific mode: power, square root (check the domains).