javascript - 从现有地图初始化地图

Question

假设我们有一个现有的地图：

const m1 = new Map([['color', 'red'], ['owner', 'Flavio'], ['age', 2]])

如果我们想创建一个新地图，是否足够：

const m2 = new Map(m1);

或者也许相反：

const m2 = new Map(Array.from(m1))

Answer 1

MDN 说你可以做到这一点。

const first = new Map([
  [1, "one"],
  [2, "two"],
  [3, "three"]
]);

const second = new Map([
  [1, "uno"],
  [2, "dos"],
  [3, "tres"]
]);

const merged = new Map([...first, ...second]);

console.log(merged.get(1))