将二维 JavaScript 数组转换为一维数组

Convert a 2D JavaScript array to a 1D array

提问by Anderson Green

I want to convert a 2D JavaScript array to a 1D array, so that each element of the 2D array will be concatenated into a single 1D array.

我想将二维 JavaScript 数组转换为一维数组，以便将二维数组的每个元素连接成一个一维数组。

Here, I'm trying to convert arrToConvertto a 1D array.

在这里，我试图转换arrToConvert为一维数组。

var arrToConvert = [[0,0,1],[2,3,3],[4,4,5]];

console.log(get1DArray(arrToConvert)); //print the converted array

function get1DArray(2dArr){
    //concatenate each element of the input into a 1D array, and return the output
    //what would be the best way to implement this function?
}

回答by Bla? Zupan?i?

Use the ES6 Spread Operator

使用 ES6 扩展运算符

arr1d = [].concat(...arr2d);

Note that this method is only works if arr2dhas less than about 100 000 subarrays. If your array gets larger than that you will get a RangeError: too many function arguments.

请注意，此方法仅适用arr2d于少于大约 100 000 个子阵列的情况。如果您的数组变得更大，您将获得一个RangeError: too many function arguments.

For > ~100 000 rows

对于 > ~100 000 行

arr = [];
for (row of table) for (e of row) arr.push(e);

concat()is too slow in this case anyway.

concat()无论如何在这种情况下太慢了。

The Underscore.js way

Underscore.js 方式

This will recursively flatten arrays of any depth (should also work for large arrays):

这将递归地展平任何深度的数组（也应该适用于大型数组）：

arr1d = _.flatten(arr2d);

If you only want to flatten it a single level, pass trueas the 2nd argument.

如果您只想将其展平一个级别，请将其true作为第二个参数传递。

A short < ES6 way

一个简短的 < ES6 方式

arr1d = [].concat.apply([], arr2d);

回答by Marty

Try .concat():

尝试.concat()：

var arrToConvert = [[0,0,1],[2,3,3],[4,4,5]];
var newArr = [];


for(var i = 0; i < arrToConvert.length; i++)
{
    newArr = newArr.concat(arrToConvert[i]);
}

console.log(newArr);

回答by marteljn

How about:

怎么样：

var arrToConvert = [[0,0,1],[2,3,3],[4,4,5]];

function get1DArray(arr){
    return arr.join().split(",");
}

console.log(get1DArray(arrToConvert));

http://jsfiddle.net/JRR4J/

http://jsfiddle.net/JRR4J/

回答by blvz

Try .reduce()

尝试 .reduce()

var test2d = [
  ["foo", "bar"],
  ["baz", "biz"]
];
var merged = test2d.reduce(function(prev, next) {
  return prev.concat(next);
});

Source: http://jsperf.com/2-dimensional-array-merge

来源：http: //jsperf.com/2-dimensional-array-merge

回答by Balasubramanian

var arrToConvert = [[0,0,1],[2,3,3],[4,4,5]];

var modifiedArray = arrToConvert.map(function(array){ 
    return array[0]+array[1]+array[2];
});

Another Example

另一个例子

var passengers = [ 
  ["Thomas", "Meeks"],
  ["Gregg", "Pollack"],
  ["Christine", "Wong"],
  ["Dan", "McGaw"]
];

var modifiedNames = passengers.map(function(convArray){
    return convArray[0]+" "+convArray[1];
});

回答by Saturnix

var arrToConvert = [[0, 0, 1], [2, 3, 3], [4, 4, 5]];

function get1DArray(arr){

    var result = new Array();

    for (var x = 0; x < arr.length; x++){
        for (var y = 0; y < arr[x].length; y++){

        result.push(arr[x][y])

        }
    }

    return result
}


alert (get1DArray(arrToConvert))

http://jsfiddle.net/Saturnix/ReeqQ/

http://jsfiddle.net/Saturnix/ReeqQ/