thinking in java 书中源码 第四版

				//: arrays/RaggedArray.java
				import java.util.*;
				
				public class RaggedArray {
				  public static void main(String[] args) {
				    Random rand = new Random(47);
				    // 3-D array with varied-length vectors:
				    int[][][] a = new int[rand.nextInt(7)][][];
				    for(int i = 0; i < a.length; i++) {
				      a[i] = new int[rand.nextInt(5)][];
				      for(int j = 0; j < a[i].length; j++)
				        a[i][j] = new int[rand.nextInt(5)];
				    }
				    System.out.println(Arrays.deepToString(a));
				  }
				} /* Output:
				[[], [[0], [0], [0, 0, 0, 0]], [[], [0, 0], [0, 0]], [[0, 0, 0], [0], [0, 0, 0, 0]], [[0, 0, 0], [0, 0, 0], [0], []], [[0], [], [0]]]
				*///:~