使用Collections API Shuffle [英] Using Collections API to Shuffle

问题描述

我感到非常沮丧，因为我似乎不知道为什么集合shuffling不能正常工作。

I am getting very frustrated because I cannot seem to figure out why Collections shuffling is not working properly.

我想说，我试图洗牌 randomizer 数组。

Lets say that I am trying to shuffle the randomizer array.

int[] randomizer = new int[] {200,300,212,111,6,2332}; 
Collections.shuffle(Arrays.asList(randomizer));

由于某种原因，元素保持排序完全相同，无论我是否调用shuffle方法。有任何想法吗？

For some reason the elements stay sorted exactly the same whether or not I call the shuffle method. Any ideas?

推荐答案

Arrays.asList 不能与基元数组一起使用。请改用：

Arrays.asList cannot be used with arrays of primitives. Use this instead:

Integer[] randomizer = new Integer[] {200,300,212,111,6,2332}; 
Collections.shuffle(Arrays.asList(randomizer));

同样的规则适用于集合框架中的大多数类，因为您不能使用原始类型。

The same rule applies to most classes in the collections framework, in that you can't use primitive types.

原始代码（带有 int [] ）编译正常，但没有按预期工作，因为可变参数方法的行为 asList ：它只是一个单元素列表，只有 int 数组

The original code (with int[]) compiled fine, but did not work as intended, because of the behaviour of the variadic method asList: it just makes a one-element list, with the int array as its only member.

这篇关于使用Collections API Shuffle的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！