int [，]和int [] []之间的区别是什么？ [英] What Is The Difference Between int [,] And int [] [] ?

问题描述

int [，]和int [] []之间的区别是什么？我也想知道为什么它会通过语法提到下面的错误提示



int [，] a = new int [5,2] {{0,0}，{1,2}，{2,4}，{3,6}，{4,8}}; //工作正常



int [] [] b = new int [5,2] {{0,0}，{1,2}，{2， 4}，{3,6}，{4,8}}; //抛出错误



int [] [] c = {{1,2,3}，{11,12,13}}; //抛出错误

What Is The Difference Between int [,] And int [] [] And I Also Want To Know That Why It Throws A Error By Going Through Syntax Mention Below

int[,] a = new int[5, 2] { { 0, 0 }, { 1, 2 }, { 2, 4 }, { 3, 6 }, { 4, 8 } }; // work fine

int[] [] b = new int[5, 2] { { 0, 0 }, { 1, 2 }, { 2, 4 }, { 3, 6 }, { 4, 8 } }; // throws a error

int[][] c = { { 1, 2, 3 }, { 11, 12, 13 } }; // throws error

推荐答案

你弄错了。

You got it wrong.

int[,] a

是一个二维数组

而

is a 2-dimensional array
while

int[][] b

是一个数组数组，即每个元素本身就是一个数组，例如

is an array of arrays, i.e. each element is an array itself, e.g.

int[][] b = new int[5][] { new int[] {1,2}, new int[] {3,4}, new int[] {5,6}, new int[] {7,8}, new int[] {9,0} };

了解更多 https://msdn.microsoft.com/en -us / library / aa288453（v = vs.71）.aspx [ ^ ]

以下声明创建一个包含四行的二维数组两列。

The following declaration creates a two-dimensional array of four rows and two columns.

int[,] array = new int[4, 2];
// 2d array
int[,] 2dArray = new int[,] { { 1, 2 }, { 3, 4 }, { 5, 6 }, { 7, 8 } };

以下是锯齿状数组的声明：单维数组，有三个元素，每个元素其中一个是整数的一维数组：

The following is a declaration of a jagged-array : single-dimensional array that has three elements, each of which is a single-dimensional array of integers:

int[][] jaggedArray = new int[3][];

在使用jaggedArray之前，必须初始化其元素。你可以像这样初始化元素：

Before you can use jaggedArray, its elements must be initialized. You can initialize the elements like this:

jaggedArray[0] = new int[5];
jaggedArray[1] = new int[4];
jaggedArray[2] = new int[2];

每个元素都是一维整数数组。第一个元素是一个5个整数的数组，第二个是4个整数的数组，第三个是2个整数的数组。



从这里：

多维数组 [ ^ ]

锯齿状阵列 [ ^ ]



-KR

Each of the elements is a single-dimensional array of integers. The first element is an array of 5 integers, the second is an array of 4 integers, and the third is an array of 2 integers.

From here:
Multidimensional Arrays[^]
Jagged Arrays[^]

-KR

区别在于[ ，]是一个2D固定大小的数组，包含正好x * y个元素，当你在 new 赋值中分配空格时给出x和y：

The difference is that [,] is a 2D fixed size array containing exactly x * y elements, where x and y are given when you allocate the space in the new assignment:

int[,] arr = new int[x,y];

[] []创建一个锯齿状的arra y，你一次只分配一个维度：

[][] creates a jagged array, where you only assign one dimension at a time:

int[][] arr = new int[x][];
for(int i = 0; i < x; i++)
   {
   arr[i] = new int[(i + 1) * 2];
   }

锯齿状数组的每个元素可以是不同的大小，需要使用单独的 new 语句进行分配。 />


虽然您可以使用以下语法初始化固定大小的数组：

Each element of the jagged array can be a different size, and needs to be allocated with a separate new statement.

While you can initialize fixed size arrays with this syntax:

int[,] arr = new int[5, 2] { { 0, 0 }, { 1, 2 }, { 2, 4 }, { 3, 6 }, { 4, 8 } };

你需要这个语法来做一个锯齿状数组：

You need this syntax to do the same with a jagged array:

int[][] arr = new int[5][] { new int[] { 0, 0 }, 
                             new int[] { 1, 2 }, 
                             new int[] { 2, 4 }, 
                             new int[] { 3, 6 }, 
                             new int[] { 4, 8 } };

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