Added Calculator Feature

Author: KaziRifatAlMuin

src/main/Calculator.java

@@ -0,0 +1,26 @@
+public class Calculator {
+
+    // Method to add two numbers
+    public int add(int a, int b) {
+        return a + b;
+    }
+
+    // Method to subtract two numbers
+    public int subtract(int a, int b) {
+        return a - b;
+    }
+
+    // Method to multiply two numbers
+    public int multiply(int a, int b) {
+        return a * b;
+    }
+
+    // Method to divide two numbers
+    public double divide(int a, int b) {
+        if (b != 0) {
+            return (double) a / b;
+        } else {
+            throw new ArithmeticException("Division by zero is not allowed.");
+        }
+    }
+}