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function ppp(){ var a = 2; sss = function(){ console.log(a); } } ppp(); sss();
这里能打印2感觉很神奇，因为2在ppp函数作用域里面,sss在外面执行竟然能拿到值
A question about js? -PHP Chinese website Q&A-A question about js? -PHP Chinese website Q&A
Let’s take a look and learn.
你的理解完全错了， 首先 你这样 直接写 a =2； 实际相当于 声明了个全局变量 ，你可以理解为 window.a =2;当然能拿到。
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
A question about js? -PHP Chinese website Q&A-A question about js? -PHP Chinese website Q&A
Let’s take a look and learn.
你的理解完全错了， 首先 你这样 直接写 a =2； 实际相当于 声明了个全局变量 ，你可以理解为 window.a =2;当然能拿到。