1.中文版P232页，英文版P415

为什么程序实际运行结果输出为：

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]

Here’s an example that uses a HashSet with Integer objects://: holding/SetOfInteger.javaimport 

java.util.*;

public class SetOfInteger {

public static void main(String[] args) {Random rand = new Random(47);Setintset = new HashSet();

for(int i = 0; i < 10000; i++)

intset.add(rand.nextInt(30));

System.out.println(intset);

}

} /* Output:

[15, 8, 23, 16, 7, 22, 9, 21, 6, 1, 29, 14, 24, 4, 19, 26, 11, 18, 3, 12, 27, 17, 2, 13, 28, 20, 25, 10, 5, 0]

*///:~