摘要：
1.var a=12 function fn(){ console.log(a) //undefined var a=45 console.log(a) //45 } fn() 案例解析画图： 2.var a=12; function fn(){ console.log(a) //12 a=45 c 阅读全文
摘要：
作用域面试题： 1. fn() function fn () { console.log(12) } var as = function () { console.log(45) } 2. var a = 12; function fn () { console.log(a) var a = 45; 阅读全文