我将从对我英语不好的人道歉开始。我会尽量保持清楚。 :)
I will start with an apology about my poor English. I will try to be as clear as I can. :)
我有一个3维数组(只是2维数组的数组)。我的目标是采用二维数组之一,并将其逆时针旋转90°。看起来像这样:
I have a 3-dimensional array (just an array of 2-dimensional arrays). My goal is to take one of the 2-dimensional arrays, and rotate it 90° counterclockwise. It look like this:
[1|2|3] [4|5|6] [7|8|9]我尝试使它像这样旋转:
I try to make it "rotate" like this:
[3|6|9] [2|5|8] [1|4|7]我想更改原始数组,所以我想需要创建一个副本所以我将为您提供参考。所以,这就是我所做的:
I want to change the original array, so I figured that I need to create a copy of it so i will have a reference to work with. So, here is what I have done:
var temp = []; var cube = [ [ ['A', 'A', 'A'], ['A', 'A', 'A'], ['A', 'A', 'A'] ], [ ['B', 'B', 'B'], ['B', 'B', 'B'], ['B', 'B', 'B'] ], [ ['C', 'C', 'C'], ['C', 'C', 'C'], ['C', 'C', 'C'] ], [ ['D', 'D', 'D'], ['D', 'D', 'D'], ['D', 'D', 'D'] ], [ ['1', '2', '3'], ['4', '5', '6'], ['7', '8', '9'] ], [ ['F', 'F', 'F'], ['F', 'F', 'F'], ['F', 'F', 'F'] ] ]; function CCW() { temp = temp.concat(cube[4]); for(var i = 0; i < 3; i++) for(var j = 0; j < 3; j++) cube[4][i][j] = temp[j][2-i]; } CCW();原始数组的副本应位于 temp 。
The copy of the original array should be in temp.
现在,问题出在这一行: cube [4] [i] [j] = temp [j] [2 -i]; 。除了更改 cube 中的数组的值外,它还更改 temp 的值。我试图将 temp = temp.concat(cube [4]); 更改为 temp = cube [4] .slice(0); ,但没有任何区别。
Now, the problem is in this line: cube[4][i][j] = temp[j][2-i];. Instead of changing only the values of the array in cube, it changes also the values of temp. I tried to change temp = temp.concat(cube[4]); to temp = cube[4].slice(0); but it did not make any diffrence.
我该如何解决?谢谢你们。 :)
How can I fix that? Thank you all. :)
推荐答案直接分配数组时,它是javascript中的引用分配。这意味着任何更改都将反映在两者中。要复制数组,您需要调用array.slice()。
when you assign an array directly, it is a reference assignment in javascript. This means that any changes will be reflected in both. To copy an array, you will need to call array.slice().
注意:这仍然是多维数组上的赋值,因此您需要写一些递归的东西来复制一个具有多个维度的数组(在任何元素上,例如[1、2,['some','inner','array'],3])
note: this will still be an assignment on a multi-dimensional array, so you will need to write something recursive to copy an array that has more than one dimension (at any element, e.g. [1, 2, ['some', 'inner', 'array'], 3])
可以清除这种东西吗?
编辑:这是一个deepCopyArray函数,需要将其扩展为任意对象,不过...
edit: here's a deepCopyArray function, this needs to be exanded for arbitrary objects, though...
function deepCopyArray(arr) { var newArr = []; for (var i = 0; i < arr.length; i++) { var a = arr[i], ele; if (a instanceof Array) //current element is an array... ele = deepCopyArray(a); else ele = a; newArr.push(ele); } return newArr; }更多推荐
创建数组的副本并处理原始数组
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