实现
<body>
<!-- 填写标签 -->
<script type="text/javascript">
// 填写JavaScript
Array.prototype._filter = function(Fn) {
if(typeof Fn !== 'function')return
const newArr = []
for(let i = 0;i < this.length;i++){
Fn(this[i])?newArr.push(this[i]):null
}
return newArr
}
</script>
</body>
