哪个优先？窗口API和编译阶段？

Question

我想知道bind()是否比初始化变量更快地执行？

 I found obj is undefined when bind() is executed     I've learned variables hoisting but I don't understand this situation about executing orders when Window APIs join in .

 var obj = {
   foo:(function(){
     return this
   }).bind(obj)
 }

obj.foo() //Window

Answer 1

问题是，当它们表示对象中的键值时，由于未初始化对象变量，因此无法访问对象变量。

​

var obj = {
   test:obj
}
console.log(obj.test) //undefined

​

我想知道bind()是否比初始化变量更快地执行？

是的，它在对象初始化之前执行。