Javascript 如何使用Javascript将简单数组转换为二维数组（矩阵）
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How to convert simple array into two-dimensional array (matrix) with Javascript
提问by Bakhtiyor
Imagine I have an array:
想象一下我有一个数组：
A = Array(1, 2, 3, 4, 5, 6, 7, 8, 9);
And I want it to convert into 2-dimensional array (matrix of N x M), for instance like this:
我希望它转换为二维数组（N x M 矩阵），例如这样：
A = Array(Array(1, 2, 3), Array(4, 5, 6), Array(7, 8, 9));
Note, that rows and columns of the matrix is changeable.
请注意，矩阵的行和列是可变的。
回答by jwueller
Something like this?
像这样的东西？
function listToMatrix(list, elementsPerSubArray) {
var matrix = [], i, k;
for (i = 0, k = -1; i < list.length; i++) {
if (i % elementsPerSubArray === 0) {
k++;
matrix[k] = [];
}
matrix[k].push(list[i]);
}
return matrix;
}
Usage:
用法：
var matrix = listToMatrix([1, 2, 3, 4, 4, 5, 6, 7, 8, 9], 3);
// result: [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
回答by samanime
You can use the Array.prototype.reducefunction to do this in one line.
您可以使用该Array.prototype.reduce函数在一行中完成此操作。
ECMAScript 6 style:
ECMAScript 6 风格：
myArr.reduce((rows, key, index) => (index % 3 == 0 ? rows.push([key])
: rows[rows.length-1].push(key)) && rows, []);
"Normal" JavaScript:
“普通”JavaScript：
myArr.reduce(function (rows, key, index) {
return (index % 3 == 0 ? rows.push([key])
: rows[rows.length-1].push(key)) && rows;
}, []);
You can change the 3 to whatever you want the number of columns to be, or better yet, put it in a reusable function:
您可以将 3 更改为您想要的列数，或者更好的是，将其放入可重用的函数中：
ECMAScript 6 style:
ECMAScript 6 风格：
const toMatrix = (arr, width) =>
arr.reduce((rows, key, index) => (index % width == 0 ? rows.push([key])
: rows[rows.length-1].push(key)) && rows, []);
"Normal" JavaScript:
“普通”JavaScript：
function toMatrix(arr, width) {
return arr.reduce(function (rows, key, index) {
return (index % width == 0 ? rows.push([key])
: rows[rows.length-1].push(key)) && rows;
}, []);
}
回答by Bhanu Prakash H c
This code is generic no need to worry about size and array, works universally
此代码是通用的，无需担心大小和数组，通用
function TwoDimensional(arr, size)
{
var res = [];
for(var i=0;i < arr.length;i = i+size)
res.push(arr.slice(i,i+size));
return res;
}
- Defining empty array.
- Iterate according to the size so we will get specified chunk.That's why I am incrementing iwith size, because size can be 2,3,4,5,6......
- Here, first I am slicing from ito (i+size)and then I am pushing it to empty array res.
- Return the two-dimensional array.
- 定义空数组。
- 根据大小迭代，所以我们会得到指定的块。这就是为什么我用size递增i，因为大小可以是 2,3,4,5,6......
- 在这里，首先我从i切片到(i+size)然后我将它推送到空数组res。
- 返回二维数组。
回答by Andrew Whitaker
How about something like:
怎么样：
var matrixify = function(arr, rows, cols) {
var matrix = [];
if (rows * cols === arr.length) {
for(var i = 0; i < arr.length; i+= cols) {
matrix.push(arr.slice(i, cols + i));
}
}
return matrix;
};
var a = [0, 1, 2, 3, 4, 5, 6, 7];
matrixify(a, 2, 4);
回答by Vincent Mimoun-Prat
Simply use two for loops:
只需使用两个 for 循环：
var rowNum = 3;
var colNum = 3;
var k = 0;
var dest = new Array(rowNum);
for (i=0; i<rowNum; ++i) {
var tmp = new Array(colNum);
for (j=0; j<colNum; ++j) {
tmp[j] = src[k];
k++;
}
dest[i] = tmp;
}
回答by cwallenpoole
function matrixify( source, count )
{
var matrixified = [];
var tmp;
// iterate through the source array
for( var i = 0; i < source.length; i++ )
{
// use modulous to make sure you have the correct length.
if( i % count == 0 )
{
// if tmp exists, push it to the return array
if( tmp && tmp.length ) matrixified.push(tmp);
// reset the temporary array
tmp = [];
}
// add the current source value to the temp array.
tmp.push(source[i])
}
// return the result
return matrixified;
}
If you want to actually replace an array's internal values, I believe you can call the following:
如果你想真正替换一个数组的内部值，我相信你可以调用以下内容：
source.splice(0, source.length, matrixify(source,3));
回答by Calle Bergstr?m
The cleanest way I could come up with when stumbling across this myself was the following:
当我自己偶然发现这个问题时，我能想到的最干净的方法如下：
const arrayToMatrix = (array, columns) => Array(Math.ceil(array.length / columns)).fill('').reduce((acc, cur, index) => {
return [...acc, [...array].splice(index * columns, columns)]
}, [])
where usage would be something like
使用情况类似于
const things = [
'item 1', 'item 2',
'item 1', 'item 2',
'item 1', 'item 2'
]
const result = arrayToMatrix(things, 2)
where result ends up being
结果最终在哪里
[
['item 1', 'item 2'],
['item 1', 'item 2'],
['item 1', 'item 2']
]
回答by p8ul
This a simple way to convert an array to a two-dimensional array, especially when you want to manipulate array items generated.
这是一种将数组转换为二维数组的简单方法，尤其是当您要操作生成的数组项时。
const arr = [1,2,3,4,5,6,7,8,9]
let i = 0;
let twoDimension = [];
while (i < arr.length) {
const first = arr[i];
const second = arr[i + 1];
const third = arr[i + 2]
let tempArr = []
if (first && second && third) {
tempArr.push(first, second, third)
} else if (first && second) {
tempArr.push(first, second)
} else {
tempArr.push(first)
}
twoDimension[twoDimension.length] = tempArr;
i += 3;
}
console.log(twoDimension)
回答by SayedRakib
function chunkArrToMultiDimArr(arr, size) {
var newArray = [];
while(arr.length > 0)
{
newArray.push(arr.slice(0, size));
arr = arr.slice(size);
}
return newArray;
}
//example - call function
chunkArrToMultiDimArr(["a", "b", "c", "d"], 2);
回答by Jannic Beck
function matrixify(array, n, m) {
var result = [];
for (var i = 0; i < n; i++) {
result[i] = array.splice(0, m);
}
return result;
}
a = matrixify(a, 3, 3);
