import books from "./books.json";

export const getAllBooks = () => {
  return {
    data: books,
    // a=accoumulator, b=book (data itelf), i=index
    bookMap: books.reduce((a, book, i) => {
      // since we passed {} as initial data, initially a={}
      // {bookID1:book1, bookID2:i}
      a[book.id] = book;
      // you can add new property index
      a[book.id].index=i
      return a;
      // we are passing initial data structure
    }, {}),
  };
};

令I = 0; let myArray = ["first"， "second"， "third"， "fourth"]; const arrayToObject = (arr) => 对象。分配(arr{},……。Map (item => ({[i++]: item}))); console.log (arrayToObject (myArray));

或使用

myArray = ["first"， "second"， "third"， "fourth"] console.log (myArray{…})

更面向对象的方法:

Array.prototype.toObject = function() {
 var Obj={};

 for(var i in this) {
  if(typeof this[i] != "function") {
   //Logic here
   Obj[i]=this[i];
  }
 }

 return Obj;
}

快速和肮脏的#2:

var i = 0
  , s = {}
  , a = ['A', 'B', 'C'];

while( i < a.length ) { s[i] = a[i++] };

这是我刚刚写的递归函数。这很简单，而且效果很好。

// 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;
}

下面是一个例子(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));

结果:

FWIW，另一种最近的方法是使用Object. fromentries和Object。条目如下:

const arr = ['a','b','c'];
arr[-2] = 'd';
arr.hello = 'e';
arr.length = 17;
const obj = Object.fromEntries(Object.entries(arr));

.．.它允许避免将稀疏数组项存储为未定义或空，并保留非索引(例如，非正整数/非数字)键。

{0: "a"， 1: "b"， 2: "c"， "-2": "d"， hello: "e"}

(这里的结果与@Paul Draper的对象相同。分配的答案。)

你可能希望加上arr。长度，但不包括在内:

obj.length = arr.length;