// This brief example demonstrates how to test for valid
// user input (in this case, an integer).

import java.util.*;

public class ValidInput {
    public static void main(String[] args) {
        Scanner console = new Scanner(System.in);
        
        System.out.print("Type a number: ");
        if (console.hasNextInt()) {
            int num = console.nextInt();
            System.out.println("You typed " + num);
        } else {
            System.out.println("Invalid number.");
        }
    }
}