Java Basic Programs for Beginners

Which of the following is a valid Java identifier?

What is the output of the following program?

public class Main {
public static void main(String[] args) {
int x = 5;
int y = ++x * 2;
System.out.println(y);
 }
}

What is the output of the following program?

public class Main {
public static void main(String[] args) {
int[] arr = {1, 2, 3, 4, 5};
for (int i = 0; i < arr.length; i++) {
System.out.print(arr[i] + " ");
  }
 }
}