将数组转换为对象
本文翻译自：Convert Array to Object
What is the best way to convert: 转换的最佳方式是什么：
['a','b','c']
to: 至：
{
0: 'a',
1: 'b',
2: 'c'
}
#1楼
参考：https://stackoom.com/question/Hghl/将数组转换为对象
#2楼
Quick and dirty #2: 快速而肮脏的＃2：
var i = 0
, s = {}
, a = ['A', 'B', 'C'];
while( a[i] ) { s[i] = a[i++] };
#3楼
Here's a solution in coffeescript 这是coffeescript的解决方案
arrayToObj = (arr) ->
obj = {}
for v,i in arr
obj[i] = v if v?
obj
#4楼
This allows you to generate from an array an object with keys you define in the order you want them. 这允许您从数组生成一个对象，该对象具有您按照所需顺序定义的键。
Array.prototype.toObject = function(keys){
var obj = {};
var tmp = this; // we want the original array intact.
if(keys.length == this.length){
var c = this.length-1;
while( c>=0 ){
obj[ keys[ c ] ] = tmp[c];
c--;
}
}
return obj;
};
result = ["cheese","paint",14,8].toObject([0,"onion",4,99]);
console.log(">>> :" + result.onion); will output "paint", the function has to have arrays of equal length or you get an empty object. 将输出“paint”，该函数必须具有相等长度的数组，否则您将得到一个空对象。
Here is an updated method 这是一个更新的方法
Array.prototype.toObject = function(keys){
var obj = {};
if( keys.length == this.length)
while( keys.length )
obj[ keys.pop() ] = this[ keys.length ];
return obj;
};
#5楼
You could use an accumulator aka reduce . 你可以使用累加器aka reduce 。
['a','b','c'].reduce(function(result, item, index, array) {
result[index] = item; //a, b, c
return result;
}, {}) //watch out the empty {}, which is passed as "result"
Pass an empty object {} as a starting point; 传递空对象{}作为起点; then "augment" that object incrementally. 然后逐渐“增加”该对象。 At the end of the iterations, result will be {"0": "a", "1": "b", "2": "c"} 在迭代结束时， result将为{"0": "a", "1": "b", "2": "c"}
If your array is a set of key-value pair objects: 如果您的数组是一组键值对对象：
[{ a: 1},{ b: 2},{ c: 3}].reduce(function(result, item) {
var key = Object.keys(item)[0]; //first property: a, b, c
result[key] = item[key];
return result;
}, {});
will produce: {a: 1, b: 2, c: 3} 将产生： {a: 1, b: 2, c: 3}
For the sake of completeness, reduceRight allows you to iterate over your array in reverse order: 为了完整起见， reduceRight允许您以相反的顺序迭代数组：
[{ a: 1},{ b: 2},{ c: 3}].reduceRight(/* same implementation as above */)
will produce: {c:3, b:2, a:1} 将产生： {c:3, b:2, a:1}
Your accumulator can be of any type for you specific purpose. 您的累加器可以是任何类型的特定用途。 For example in order to swap the key and value of your object in an array, pass [] : 例如，为了在数组中交换对象的键和值，传递[] ：
[{ a: 1},{ b: 2},{ c: 3}].reduce(function(result, item, index) {
var key = Object.keys(item)[0]; //first property: a, b, c
var value = item[key];
var obj = {};
obj[value] = key;
result.push(obj);
return result;
}, []); //an empty array
will produce: [{1: "a"}, {2: "b"}, {3: "c"}] 将产生： [{1: "a"}, {2: "b"}, {3: "c"}]
Unlike map , reduce may not be used as a 1-1 mapping. 与map不同， reduce不能用作1-1映射。 You have full control over the items you want to include or exclude. 您可以完全控制要包含或排除的项目。 Therefore reduce allows you to achieve what filter does, which makes reduce very versatile: 因此， reduce可以让你实现filter功能，这使得reduce非常通用：
[{ a: 1},{ b: 2},{ c: 3}].reduce(function(result, item, index) {
if(index !== 0) { //skip the first item
result.push(item);
}
return result;
}, []); //an empty array
will produce: [{2: "b"}, {3: "c"}] 将产生： [{2: "b"}, {3: "c"}]
Caution : reduce and Object.key are part of ECMA 5th edition ; 注意 ： reduce和Object.key是ECMA 5th edition一部分; you should provide a polyfill for browsers that don't support them (notably IE8). 你应该为不支持它们的浏览器提供polyfill（特别是IE8）。
See a default implementation by Mozilla . 请参阅Mozilla的默认实现。
#6楼
Here's a recursive function I just wrote. 这是我刚写的一个递归函数。 It's simple and works well. 这很简单，效果很好。
// Convert array to object
var convArrToObj = function(array){
var thisEleObj = new Object();
if(typeof array == "object"){
for(var i in array){
var thisEle = convArrToObj(array[i]);
thisEleObj[i] = thisEle;
}
}else {
thisEleObj = array;
}
return thisEleObj;
}
Here's an example ( jsFiddle ): 这是一个例子（ jsFiddle ）：
var array = new Array();
array.a = 123;
array.b = 234;
array.c = 345;
var array2 = new Array();
array2.a = 321;
array2.b = 432;
array2.c = 543;
var array3 = new Array();
array3.a = 132;
array3.b = 243;
array3.c = 354;
var array4 = new Array();
array4.a = 312;
array4.b = 423;
array4.c = 534;
var array5 = new Array();
array5.a = 112;
array5.b = 223;
array5.c = 334;
array.d = array2;
array4.d = array5;
array3.d = array4;
array.e = array3;
console.log(array);
// Convert array to object
var convArrToObj = function(array){
var thisEleObj = new Object();
if(typeof array == "object"){
for(var i in array){
var thisEle = convArrToObj(array[i]);
thisEleObj[i] = thisEle;
}
}else {
thisEleObj = array;
}
return thisEleObj;
}
console.log(convArrToObj(array));
Results: 结果：