Map,Set,Array,Object之间的相互转换
原生js能够支持这几种类型数据格式之间的转换，先了解下Object.entries和Object.FromEntries这两个原生方法的作用。
Object.entries获取对象的键值对
Object.FromEntries把键值对列表转成对象
Object.entries和Object.fromEntries之间是可逆的。
1，Object转Map
let arr={foo:'hello',bar:100};
let map=new Map(Object.entries(arr));
console.log(map)
2,Map转Object
let map=new Map([['foo','hello'],['bar',100]]);
let obj=Object.fromEntries(map);
console.log(obj);
3,Object转Array
let obj={'foo':'hello','bar':100};
let arr=Object.entries(obj);
console.log(arr);
4,Array转成Object
let arr=[['foo','hello'],['bar',100]];
let obj=Object.fromEntries(arr);
console.log(obj);
5,Object转Set
let obj={'foo':'hello','bar':100};
let set=new Set(obj);
6,Set转Object
let obj={'foo':'hello','bar':100};
let set=new Set(obj);
let newObj=Object.formEntries(set);
console.log(newObj);
7,Array转Set
let arr=[['foo','hello'],['bar',100]];
let set=new Set(arr);
console.log(set)