推（）的二维阵列用JavaScript [英] push() a two-dimensional array with JavaScript

问题描述

我试图推到一个二维数组没有它搞乱了，目前我的数组是：

I'm trying to push to a two-dimensional array without it messing up, currently My array is:

var myArray = [
[1,1,1,1,1],
[1,1,1,1,1],
[1,1,1,1,1]
]

和我的code我想的是：

And my code I'm trying is:

var r = 3; //start from rows 3
var c = 5; //start from col 5

var rows = 8;
var cols = 7;

for (var i = r; i < rows; i++)
{
    for (var j = c; j < cols; j++)
    {
        myArray[i][j].push(0);
    }
}

这应该导致以下内容：

var myArray = [
[1,1,1,1,1,0,0],
[1,1,1,1,1,0,0],
[1,1,1,1,1,0,0],
[0,0,0,0,0,0,0],
[0,0,0,0,0,0,0],
[0,0,0,0,0,0,0],
]

但它没有，也不知道这是否是做或不正确的方法。

But it doesn't and not sure whether this is the correct way to do it or not.

所以，问题是我会怎样做到这一点？

So the question is how would I accomplish this?

感谢。

推荐答案

您在你的code一些错误：

You have some errors in your code:

1. 使用 myArray的[I] .push（0）; 来添加新列。您code（ myArray的[I] [J] .push（0）; ）的3维数组来完成工作，因为它试图另一个元素添加到数组在位置 [I] [J] 。


2. 您不仅扩大（COL-D）中的所有行-many列，即使在那些，这还没有被初始化，因此没有条目为止。

1. Use myArray[i].push( 0 ); to add a new column. Your code (myArray[i][j].push(0);) would work in a 3-dimensional array as it tries to add another element to an array at position [i][j].
2. You only expand (col-d)-many columns in all rows, even in those, which haven't been initialized yet and thus have no entries so far.

一个正确的，但那种详细的版本，会是以下内容：

One correct, although kind of verbose version, would be the following:

var r = 3; //start from rows 3
var c = 5; //start from col 5

var rows = 8;
var cols = 7;

// expand to have the correct amount or rows
for( var i=r; i<rows; i++ ) {
  myArray.push( [] );
}

// expand all rows to have the correct amount of cols
for (var i = 0; i < rows; i++)
{
    for (var j =  myArray[i].length; j < cols; j++)
    {
        myArray[i].push(0);
    }
}

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