reduce兩個重要方法

1. arr = [1,2,2,2,2,4,5,6,6,6] hhh= arr.reduce(function(cur,next) { cur[next] ? cur[next]++ : cur[next]=1 return cur },{}) console.log(hhh)
2. let log = console.log.bind(console); let person = [ {id: 0, name: "小明"}, {id: 1, name: "小張"}, {id: 2, name: "小李"}, {id: 3, name: "小孫"}, {id: 1, name: "小周"}, {id: 2, name: "小陳"},
   ];

let obj = {};

person = person.reduce((cur,next) => { obj[next.id] ? "" : obj[next.id] = true && cur.push(next); return cur; },[]) //設置cur默認類型爲數組，而且初始值爲空的數組 log(person);