can't access lexical declaration `a' before initialization

时间：2019-04-17 16:46:05 收藏：0 阅读：351

<script type="text/javascript">
 alert(a);
 let a=2;
</script>
以上代码报错： 
ReferenceError: can‘t access lexical declaration `a‘ before initialization（在初始化之前，不能使用变量a）

原文：https://www.cnblogs.com/jianxingjianyuan/p/10724297.html

can&#39;t access lexical declaration `a&#39; before initialization

can't access lexical declaration `a' before initialization