Added Usernameavailibilitychecker.java

Usernameavailibilitychecker.java

@@ -0,0 +1,30 @@
+import java.util.Scanner;
+
+public class UsernameChecker {
+    public static void main(String[] args) {
+        // Predefined usernames (like taken usernames in a database)
+        String[] takenUsernames = {"nisha123", "coderX", "javaPro", "admin", "guest"};
+
+        Scanner sc = new Scanner(System.in);
+
+        System.out.print("Enter a username: ");
+        String username = sc.nextLine();
+
+        boolean available = true;
+
+        // Check if username exists in the taken list
+        for (String taken : takenUsernames) {
+            if (taken.equalsIgnoreCase(username)) {
+                available = false;
+                break;
+            }
+        }
+
+        // Show result
+        if (available) {
+            System.out.println("✅ Username is available!");
+        } else {
+            System.out.println("❌ Username already taken. Try another.");
+        }
+    }
+}