javascript - 在 Javascript 中从 2 个值和键数组构建一个 Map

Question

我想知道是否有一种简单的方法可以从键数组和值数组构建映射。例如，如果我有 2 个数组

var keys = [0, 4, 2, 3, 1];
var values = ["first", "second", "third", "fourth", "fifth"];

我打算获得这张 map :

{
  0 => 'first',
  4 => 'second',
  2 => 'third',
  3 => 'fourth',
  1 => 'fifth' }

当然，我正在寻找比以下更快的东西:

var myMap = new Map();
for (var i = 0 ; i < keys.length; i++)
myMap.set(keys[i], values[i]);

因为它的时间复杂度为 O(n)，而我寻求的东西为 O(1)

Answer 1

您正在寻找Object.assign (不适用于每个用户代理)。

The Object.assign() method is used to copy the values of all enumerable own properties from one or more source objects to a target object. It will return the target object.

var sum = ["first", "second", "third", "fourth", "fifth"],
    obj = Object.assign({}, sum);

console.log(obj);