var newArr = arr.reduce(function (prev, cur) { prev.indexOf(cur) === -1 && prev.push(cur); return prev; },[]);我才知道&&还能这么用,如果短路那我就可以理解了
var newArr = arr.reduce(function (prev, cur) { prev.indexOf(cur) === -1 && prev.push(cur); return prev; },[]);