Calculator

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "java.debug.settings.onBuildFailureProceed": true
+}

Java_Beginner_Projects/Calculator/Calculator.java

@@ -1,15 +1,18 @@
+import java.util.concurrent.Callable;
 import java.util.Scanner;// A library that permits user input in java.
+
 public class Calculator {// A simple calculator program.
 
-    Scanner scanner = new Scanner(System.in);//A variable that holds user inputs.
+    static Scanner scanner = new Scanner(System.in);// A variable that holds user inputs.
 
-    public void Menu(int Option){// A Menu method.
-        System.out.println("\t A Simple Calculator program \n\t--Menu-- \n 1. Addition \n 2. Subtraction \n 3. Multiplication \n 4. Division \n 5. Exit");
+    public static void Menu() {// A Menu method.
+        System.out.println(
+                "\t A Simple Calculator program \n\t--Menu-- \n 1. Addition \n 2. Subtraction \n 3. Multiplication \n 4. Division \n 5. Exit");
         System.out.print("Enter an option: ");
-
     }
-    //The Addition method
-    public int Add(){
+
+    // The Addition method
+    public static int Add() {
         System.out.println("\n \tAddition...");
         System.out.println("Enter your first number: ");
         int a = scanner.nextInt();
@@ -18,8 +21,9 @@ public int Add(){
         System.out.println("Answer = " + (a + b));
         return a + b;
     }
-    //The subtraction method.
-    public int Sub(){
+
+    // The subtraction method.
+    public static int Sub() {
         System.out.println("\n \tSubtraction...");
         System.out.println("Enter your first number: ");
         int a = scanner.nextInt();
@@ -30,7 +34,7 @@ public int Sub(){
     }
 
     // The multiplication method.
-    public int Mul(){
+    public static int Mul() {
         System.out.println("\n \tMultiplication...");
         System.out.println("Enter your first number: ");
         int a = scanner.nextInt();
@@ -40,61 +44,75 @@ public int Mul(){
         return a * b;
     }
 
-    //The division method.
-    public void Div(){
+    // The division method.
+    public static void Div() {
         System.out.println("\n \tDivision...");
         System.out.println("Enter your first number: ");
         int a = scanner.nextInt();
         System.out.println("Enter your second number: ");
         int b = scanner.nextInt();
-        if (b==0){
-            String zero ="Division by zero is invalid";
+        if (b == 0) {
+            String zero = "Division by zero is invalid";
             System.err.println(zero);
-        }
-        else{
+        } else {
             System.out.println("Answer = " + (a / b));
         }
     }
 
-    //A method for exit.
-    public void exit(){
-    System.out.println("Exiting...");
-}
+    // A method for exit.
+    public static void exit() {
+        System.out.println("Exiting...");
+        System.exit(0);
+    }
 
-int option;
-//Main Method.
-public void main(String [] args){
-    option = scanner.nextInt();
-    int c;
-    do{
-    Menu(option);//calling the menu method using the args option.
+    static int option;
 
-    switch (option) {
-        case 1:
-            Add();
-            break;
-        case 2:
-            Sub();
-            break;
-        case 3:
-            Mul();
-            break;
-        case 4:
-            Div();
-            break;
-        case 5:
-            exit();
-            break;
-        default:
-        System.out.println("Unknown option");
-            break;   
-    }
-    System.out.println("Do you want to continue? \n (1. Yes 2. No)");
-     c = scanner.nextInt();
-    if (c== 2){exit();}
-    else{
-        System.out.println("\n\n\n");
+    // Main Method.
+    public static void main(String[] args) {
+        int c = 0;
+        while (c == 0) {
+            Menu();
+            option = scanner.nextInt();
+
+            try {
+                switch (option) {
+                    case 1:
+                        Add();
+                        break;
+                    case 2:
+                        Sub();
+                        break;
+                    case 3:
+                        Mul();
+                        break;
+                    case 4:
+                        Div();
+                        break;
+                    case 5:
+                        exit();
+                        break;
+                    default:
+                        System.err.println("Unrecognized input");
+                        break;
+                }
+            } catch (Exception e) {
+                System.err.println("Unrecognized input");
+            }
+            System.out.println("Enter an option: Do you want to continue?\n(1. Yes\n2. No)");
+            c = scanner.nextInt();
+            switch (c) {
+                case 1:
+                    System.out.println("Continuing\n\n\n");
+                    c--;
+                    break;
+                default:
+                    exit();
+                    break;
+            }
+
+        }
+        System.err.println("Reached end of main method");
+        System.exit(1);
     }
-}while(c == 1);
 }
-}
+// modified 6/25/2026