var arr = [1,4,1,2,6,12,9,8] console.log(arr.sort()) function compare (val1, val2) { return val1 - val2 // 从小到大 // return val2 - val1 // 从大到小 } arr.sort(compare) // [1, 1, 2, 4, 6, 8, 9, 12]