The difference between arrow function and arrow function

1. Arrow functions are not bound arguments, Replace it with rest Parameters (…a) => {console.log(a)} solve  

2. Arrow function cannot be used as Generator function , Out of commission yield keyword

3. Arrow functions have no prototype properties :

(()=>{ }).prototype // undefined
(function a(){}).prototype // {constructor: ƒ}

ES6 The syntax of arrow function is added in , Arrow functions are simple and easy to obtain this Characteristics of ：

Under ordinary function this:
+ In ordinary functions this Always represents its direct caller , By default ,this refer to window,
+ In strict mode , There is no direct caller in the function of this yes undefined Use
+ call,apply,bind(ES5 newly added ) The binding of ,this refer to Bound object
 
In the arrow function this:
+ Arrow function does not have its own this, its this It's inherited ; By default, it points to the object where it was defined ( Host object ),
+ Not the object at execution time , When you define it , Maybe the environment is window, It could be something else .