Scanner input = new Scanner(System.in);
int i; // declare i outside the for loop so it’s in scope later
System.out.print("Enter from 1 up to " + x.length + " integers; ");
System.out.println("end with -999");

for (i = 0; i < x.length; i++)
{      System.out.print("Enter next integer value: "); // optional prompt
            x[i] = input.nextInt();
            if (x[i] == -999) break; // quit when sentinel value entered
}
// at this point the value in variable i is the number of inputs entered
if (i == 0)
            { System.out.println("Error: you must enter at least 1 element");
              System.exit(0); }