拾取随机字符串从Array [英] Pick Random String From Array

问题描述

我如何去从我的阵列选择一个随机字符串，但不采摘的同一个两次。

How do I go about picking a random string from my array but not picking the same one twice.

string[] names = { "image1.png", "image2.png", "image3.png", "image4.png", "image5.png" };

这可能吗？我想使用

Is this possible? I was thinking about using

return strings[random.Next(strings.Length)];

但是，这两次返回相同串的可能性。还是我错了吗？我应该用别的东西像列表来做到这一点。任何反馈是值得欢迎的。

But this has the possibility of returning the same string twice. Or am I wrong about this? Should I be using something else like a List to accomplish this. Any feedback is welcome.

推荐答案

最简单的方法（但速度慢于大型列表）是使用像列表中的一个可调整大小的容器和采摘后删除元素。这样的：

The simplest way (but slow for large lists) would be to use a resizeable container like List and remove an element after picking it. Like:

var names = new List<string> { "image1.png", "image2.png", "image3.png", "image4.png", "image5.png" };

int index = random.Next(names.Count);
var name = names[index];
names.RemoveAt(index);
return name;

当您的列表是空的，所有的值被挑选。

When your list is empty, all values were picked.

有一个更快的方法（尤其是如果您的列表很长）将是你的清单上使用一个洗牌的算法。然后，您可以一次蹦出来一个值。这将是更快，因为从一列表的末尾去除通常比从中间除去要快得多。至于洗牌，你可以在看看这个问题了解更多详情。

A faster way (especially if your list is long) would be to use a shuffling algorithm on your list. You can then pop the values out one at a time. It would be faster because removing from the end of a List is generally much faster than removing from the middle. As for shuffling, you can take a look at this question for more details.

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