Map与数组、对象之间的转换

Map转数组

const map = new Map();
map.set(1,"23").set(2,"32").set(3,"45");
const arr = [...map];
console.log(arr);

数组转Map

const arr = ["foo","bar","baz"];
const arrChangeMap = (arr) => new Map(arr.map( (value,key) => [key,value]));
console.log(arrChangeMap(arr));

Map转对象

const map = new Map();
map.set(1,"foo").set(2,"bar").set(3,"baz");
const mapChangeObj = (map) => {
     let obj = {};
     for(let [k,v] of map) {
         obj[k] = v;
     }
     return obj;
}
console.log(mapChangeObj(map));

对象转Map

const obj = {
       "1" : "foo",
       "2": "bar",
      "3" : "baz",
}
const objChangeMap = (obj) => {
      let map = new Map();
      for(let key in obj) {
           map.set(key,obj[key]);
      }
      return map;
}
console.log(objChangeMap(obj));

数组转对象

const arr= [
	{key:"a",value:'31231'},
	{key:"b",value:'31231'},
	{key:"c",value:'31231'},
	{key:"d",value:'31231'},
]
let obj = arr.reduce(
            (accumulator, current) => {
              accumulator[current.key] = current;
              return accumulator;
            },
            {}
          );
console.log(obj)