使用LINQ与n维阵列数组操作（C＃） [英] Array operations with n-dimensional array using LINQ (C#)

问题描述

假设我们有一个锯齿形阵列

Assume we have a jagged array

int[][] a = { new[] { 1, 2, 3, 4 }, new[] { 5, 6, 7, 8 }, new[] { 9, 10, 11, 12 } };

要获得第二行第二列的总和的总和，它可以被分别写入两个code线：

To get a sum of second row and sum of second column, it can be written both code lines respectively:

int rowSum = a[1].Sum();
int colSum = a.Select(row => row[1]).Sum();

但是，如果我们有2维数组的定义

But if we have definition of 2-dimensional array

int[,] a = { { 1, 2, 3, 4 }, { 5, 6, 7, 8 }, { 9, 10, 11, 12 } };

以上引用code将无法正常工作，由于compiller错误：

the above-cited code will not work due to compiller errors:

Error   1   Wrong number of indices inside []; expected 2
Error   2   'int[*,*]' does not contain a definition for 'Select' and no extension method 'Select' accepting a first argument of type 'int[*,*]' could be found (are you missing a using directive or an assembly reference?)

因此​​，问题：如何使用LINQ方法与n维数组，而不是锯齿状的？而正是一种方法来矩形阵列转换成锯齿状？

So, the question: How to use LINQ methods with n-dimensional arrays, but not jagged ones? And is where a method to convert rectangular array to jagged?

P.S。我试图找到在文档中的答案，但没有结果。

P.S. I tried to find the answer in documentation, but without result.

推荐答案

LINQ到对象是基于的IEnumerable＆LT; T＆GT;接口时，即，值的一维的序列。这意味着它不会像非交错数组n维数据结构拌匀，虽然它是可能的。

LINQ to Objects is based on the IEnumerable<T> Interface, i.e. a one-dimensional sequence of values. This means it doesn't mix well with n-dimensional data structures like non-jagged arrays, although it's possible.

可以生成整数的一维的序列索引的n维阵列

You can generate one-dimensional sequence of integers that index into the n-dimensional array:

int rowSum = Enumerable.Range(0, a.GetLength(1)).Sum(i => a[1, i]);

int colSum = Enumerable.Range(0, a.GetLength(0)).Sum(i => a[i, 1]);

这篇关于使用LINQ与n维阵列数组操作（C＃）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！