题解 | #计数#
计数
https://www.nowcoder.com/practice/628339bd8e6e440590ad86caa7ac6849?tpId=271&tqId=39602&rp=1&ru=/exam/company&qru=/exam/company&sourceUrl=%2Fexam%2Fcompany&difficulty=undefined&judgeStatus=undefined&tags=&title=
function count(arr, item) { return arr.filter(i=>i==item).length }