What is the result(array dimension)? : Questions « Utility Classes « SCJP

1. SCJP
2. Utility Classes
3. Questions

public class MainClass {
  public static void main(String[] args) {
    int[][] a = { { 1, 2, }, { 3, 4 } };
    int[] b = (int[]) a[1];
    Object o1 = a;
    int[][] a2 = (int[][]) o1;
    int[] b2 = (int[]) o1;
    System.out.println(b[1]);
  }
}