Answer:
import java.util.Scanner;
class Main {
public static void main(String args[]) {
Scanner scan = new Scanner(System.in);
System.out.print("Enter a decimal value (0 to 15): ");
int num = scan.nextInt();
scan.close();
if (num < 0 || num >15) {
System.out.printf("%d is an invalid input\n", num);
} else {
System.out.printf("The hex value is %X\n", num);
}
}
}
Explanation:
Hopefully this example will get you going for the other assignments.