如果你想转换到新的ES6地图，请这样做:

var kvArray = [['key1', 'value1'], ['key2', 'value2']];
var myMap = new Map(kvArray);

为什么要使用这种类型的地图?这取决于你。看看这个。

正如其他帖子解释的那样，有更好的方法来做到这一点。但如果我想坚持纯JS和老式的方式，那么它是:

var arr = [
    { key: 'foo', val: 'bar' },
    { key: 'hello', val: 'world' },
    { key: 'hello', val: 'universe' }
];

var map = {};
for (var i = 0; i < arr.length; i++) {
    var key = arr[i].key;
    var value = arr[i].val;

    if (key in map) {
        map[key].push(value);
    } else {
        map[key] = [value];
    }
}

console.log(map);

我会在TypeScript中说得更清楚，以防有人感兴趣。

interface Person {
  id: number;
  name: string;
}
type Result = Map<number, string>

const input: Array<Person> = [
  {
    id: 123,
    name: "naveen"
  },
  {
    id: 345,
    name: "kumar"
  },
];
const convertedToMap: Result = input.reduce(
  (map: Result, person: Person) => {
    map.set(person.id, person.name);
    return map;
  },
  new Map()
);

使用ES6 spread + Object.assign:

array = [{key: 'a', value: 'b', redundant: 'aaa'}, {key: 'x', value: 'y', redundant: 'zzz'}]

const hash = Object.assign({}, ...array.map(s => ({[s.key]: s.value})));

console.log(hash) // {a: b, x: y}

以下是我在javascript中创建的一个小片段，将对象数组转换为哈希映射，由对象的属性值索引。您可以提供一个函数来动态计算散列映射的键(运行时)。

function isFunction(func){
    return Object.prototype.toString.call(func) === '[object Function]';
}

/**
 * This function converts an array to hash map
 * @param {String | function} key describes the key to be evaluated in each object to use as key for hasmap
 * @returns Object
 * @Example 
 *      [{id:123, name:'naveen'}, {id:345, name:"kumar"}].toHashMap("id")
        Returns :- Object {123: Object, 345: Object}

        [{id:123, name:'naveen'}, {id:345, name:"kumar"}].toHashMap(function(obj){return obj.id+1})
        Returns :- Object {124: Object, 346: Object}
 */
Array.prototype.toHashMap = function(key){
    var _hashMap = {}, getKey = isFunction(key)?key: function(_obj){return _obj[key];};
    this.forEach(function (obj){
        _hashMap[getKey(obj)] = obj;
    });
    return _hashMap;
};

你可以在这里找到要点:https://gist.github.com/naveen-ithappu/c7cd5026f6002131c1fa

对我来说，我不喜欢使用任何map或reduce，只坚持简单的For循环。

const array = [
   {key: 'a', value: 'b', redundant: 'aaa'},
   {key: 'x', value: 'y', redundant: 'zzz'}
]

const hash = {};

for (const item of array) {
    hash[item.key] = item;
}

console.log(hash);