feat: Add VarArgs class demonstrating Java variable arguments (varargs)

WHAT the code does:
- Defines a `VarArgs` class showcasing different uses of varargs (`...`).
- `fun(int... v)`: accepts variable number of integers and prints them as an array.
- `demo(int... v)`: overloaded method handling integer varargs.
- `demo(String... v)`: overloaded method handling string varargs.
- `multiple(int a, int b, String... v)`: combines fixed parameters with varargs.
- `main()` demonstrates calling each method with different argument sets.

WHY this matters:
- Demonstrates how **varargs** allow flexible method calls without manually creating arrays.
- Shows **method overloading** with different vararg types.
- Useful for simplifying APIs where the number of parameters is not fixed.
- Highlights that varargs are internally treated as arrays.

HOW it works:
1. `fun(1, 2, 3, 4)` → prints `[1, 2, 3, 4]`.
2. `multiple(2, 3, "Kunal", "Rahul", "dvytsbhusc")` → prints integers and string list.
3. `demo(5, 6, 7)` → resolves to `demo(int... v)` → prints `[5, 6, 7]`.
4. `demo("A", "B", "C")` → resolves to `demo(String... v)` → prints `[A, B, C]`.

Tips & gotchas:
- Only one varargs parameter allowed per method, and it must be the last parameter.
- Varargs can be called with zero arguments (e.g., `fun()` → prints empty array).
- Ambiguity may arise if overloaded methods have similar vararg signatures.
- Varargs incur slight performance overhead since arguments are wrapped in an array.

Use-cases:
- Flexible APIs (e.g., logging methods like `log(String... messages)`).
- Utility methods where number of inputs may vary.
- Cleaner code for operations on collections of arguments.
- Educational example for **method overloading and varargs**.

Short key: class-varargs-overloading-demo.

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan

Section10Methods/Methods 2.O/src/VarArgs.java

@@ -2,24 +2,33 @@
 
 public class VarArgs {
     public static void main(String[] args) {
-//        fun();
-//        multiple(2, 3, "Kunal", "Rahul", "dvytsbhusc");
-//        demo();
+        fun(1, 2, 3, 4); // int varargs
+
+        multiple(2, 3, "Kunal", "Rahul", "dvytsbhusc"); // mixed
+
+        demo(5, 6, 7); // int varargs
+
+        demo("A", "B", "C"); // String varargs
     }
 
+    // Works with int array
     static void demo(int ...v) {
-        System.out.println(Arrays.toString(v));
+        System.out.println("Int demo: " + Arrays.toString(v));
     }
 
+    // Works with String array
     static void demo(String ...v) {
-        System.out.println(Arrays.toString(v));
+        System.out.println("String demo: " + Arrays.toString(v));
     }
 
+    // Mixed parameters: 2 fixed ints + varargs for strings
     static void multiple(int a, int b, String ...v) {
-
+        System.out.println("a = " + a + ", b = " + b);
+        System.out.println("Strings: " + Arrays.toString(v));
     }
 
+    // Simple int varargs
     static void fun(int ...v) {
-        System.out.println(Arrays.toString(v));
+        System.out.println("Fun: " + Arrays.toString(v));
     }
 }