无法理解数组声明int [] it2 = new int [] [] {{1}} [0];

Question

请有人帮我理解这个数组的创建方式.

int[] it2= new int[][]{{1}}[0];

it2是一维数组,在右边我们有奇怪的初始化类型.代码编译得很好,但我能够理解它是如何工作的.

Answer 1

打破部分表达式以更好地理解它们:

int[] first = new int[]{1}; // create a new array with one element (the element is the number one)
int[][] second = new int[][]{first}; // create an array of the arrays. The only element of the outer array is the array created in the previous step.
int[] third = second[0]; // retrieve the first (and only) element of the array of array `second`. This is the same again as `first`.

现在我们将再次合并这些表达式.首先我们合并first并second:

int[][] second = new int[][]{new int[]{1}};
int[] third = second[0];

好的,没什么大不了的.然而,表达式second可能是短暂的.以下是等效的:

int[][] second = new int[][]{{1}};
int[] third = second[0];

现在我们合并第二和第三.我们可以直接写:

int[] third = new int[][]{{1}}[0];

我们有.