是否有一个简短的for循环版本，可以循环x次? [英] Is there a shorter/simpler version of the for loop to anything x times?

问题描述

通常，我们使用计数器执行for或while循环:

Usually we do something like a for or while loop with a counter:

for (int i = 0; i < 10; i++)
{
    list.Add(GetRandomItem());
}

，但有时您会混为一谈.您可以改用while循环，但是如果您犯了一个错误，则该循环是无限的...

but sometimes you mix up with boundaries. You could use a while loop instead, but if you make a mistake this loop is infinite...

例如在Perl中，我会使用更明显的

In Perl for example I would use the more obvious

for(1..10){
    list->add(getRandomItem());
}

是否有类似 doitXtimes(10){...} 的东西?

推荐答案

您可以轻松编写自己的扩展方法:

Well you can easily write your own extension method:

public static void Times(this int count, Action action)
{
    for (int i = 0; i < count; i++)
    {
        action();
    }
}

然后您可以编写:

10.Times(() => list.Add(GetRandomItem()));

我不确定我是否真的建议您这样做，但这是一个选择.我不相信框架中有类似的东西，尽管您可以使用 Enumerable.Range 或 Enumerable.Repeat 创建一个适当长度的惰性序列，该序列可以在某些情况下会很有用.

I'm not sure I'd actually suggest that you do that, but it's an option. I don't believe there's anything like that in the framework, although you can use Enumerable.Range or Enumerable.Repeat to create a lazy sequence of an appropriate length, which can be useful in some situations.

从C#6开始，使用 using static 指令导入静态方法，您仍然可以方便地访问静态方法而无需创建扩展方法.例如:

As of C# 6, you can still access a static method conveniently without creating an extension method, using a using static directive to import it. For example:

// Normally in a namespace, of course.
public class LoopUtilities
{
    public static void Repeat(int count, Action action)
    {
        for (int i = 0; i < count; i++)
        {
            action();
        }
    }
}

然后在您想使用它时:

using static LoopUtilities;

// Class declaration etc, then:
Repeat(5, () => Console.WriteLine("Hello."));

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