如何填充/实例化单个值的C＃数组？ [英] How to populate/instantiate a C# array with a single value?

问题描述

我知道，在C＃中值类型的实例化阵列自动与默认值填充类型（如BOOL FALSE，0 INT，等等等等）。

I know that instantiated arrays of value types in C# are automatically populated with the default value of the type (eg false for bool, 0 for int, etc etc).

有没有办法来自动填充用的种子值，这不是默认的数组？无论是在创建或内置的方法之后（我相信Java有类似Array.Fill（），它做到这一点）？说我想要的，而不是虚假的布尔数组，这是默认为true。是否有一个内置的方式做到这一点，或者你只需​​要通过数组用for循环迭代？

Is there a way to autopopulate an array with a seed value that's not the default? Either on creation or a built in method afterwards (I believe Java has something like Array.Fill() which does this)? Say I wanted an boolean array that was true by default, instead of false. Is there a built in way to do this, or do you just have to iterate through the array with a for loop?

 //Example pseudo-code:
 bool[] abValues = new[1000000];
 Array.Populate(abValues, true);

 // Currently how i'm handling this:
 bool[] abValues = new[1000000];
 for (int i = 0; i < 1000000; i++)
 {
     abValues[i] = true;
 }

有通过数组进行迭代和重置的每个值设置为true似乎ineffecient。反正是有解决这个？也许通过翻转的所有值？

Having to iterate through the array and "reset" each value to true seems ineffecient. Is there anyway around this? Maybe by flipping all values?

出键入这个问题，并思考它后，我猜测，默认值是简单的C＃如何处理幕后的这些对象的内存分配的结果，所以我想它可能无法做到这一点。但我还是想知道肯定！

After typing this question out and thinking about it, I'm guessing that the default values are simply a result of how C# handles the memory allocation of these objects behind the scenes, so I imagine it's probably not possible to do this. But I'd still like to know for sure!

推荐答案

不知道一个框架的方法，但你可以写一个快速的帮手为你做它。

Don't know of a framework method but you could write a quick helper to do it for you.

public static void Populate<T>(this T[] arr, T value ) {
  for ( int i = 0; i < arr.Length;i++ ) {
    arr[i] = value;
  }
}

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