C＃：数组中的值变更为每个项目 [英] C#: Altering values for every item in an array

问题描述

如果有内置的.NET功能改变的基础上提供的委托的结果数组中的每个值我不知道。举例来说，如果我有一个数组 {1,2,3} 键，返回每个值的平方代表，我希望能够运行一个方法取数组和委托，并返回 {1,4,9} 。请问像这样的东西已经存在？

I'm wondering if there is built-in .NET functionality to change each value in an array based on the result of a provided delegate. For example, if I had an array {1,2,3} and a delegate that returns the square of each value, I would like to be able to run a method that takes the array and delegate, and returns {1,4,9}. Does anything like this exist already?

推荐答案

这并不是说我知道（更换每一个元素，而不是转换到一个新的数组或序列），但它是非常容易写：

Not that I'm aware of (replacing each element rather than converting to a new array or sequence), but it's incredibly easy to write:

public static void ConvertInPlace<T>(this IList<T> source, Func<T, T> projection)
{
    for (int i = 0; i < source.Count; i++)
    {
        source[i] = projection(source[i]);
    }
}

使用：

int[] values = { 1, 2, 3 };
values.ConvertInPlace(x => x * x);

当然，如果你真的不需要的改变现有的阵列，其他的答案使用选择将更多的功能发布。或现有的 ConvertAll 从.NET 2的方法：

Of course if you don't really need to change the existing array, the other answers posted using Select would be more functional. Or the existing ConvertAll method from .NET 2:

int[] values = { 1, 2, 3 };
values = Array.ConvertAll(values, x => x * x);

此是所有假定一维数组。如果您要包括矩形阵列，它变得棘手，特别是如果你想避免拳击。

This is all assuming a single-dimensional array. If you want to include rectangular arrays, it gets trickier, particularly if you want to avoid boxing.

这篇关于C＃：数组中的值变更为每个项目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！