具体实现请看代码:
<script> var str = 'Haveyouevergoneshopping' var isFind = false function base (target,str) { var count = 0 for (var i=0;i<str.length;i++) { if (target === str[i]) { count++ if (count === 3) { isFind = true return str[i] } } } } function find () { for (var i=0;i<str.length;i++) { base(str[i],str) if (isFind) { return base(str[i],str) break } } } var result = find() console.log(result) //返回e </script>
上述代码只是实现了这个功能,但是还可以再优化!