Eliminate the ambiguity of the function
What ambiguity means?
Normally a function can do two things
1. Instruction sequence
2. Contruction
function a() {}
a() // run the function, instruction sequence
new a() // construction
In javascript, when you see a function, you cannot make sure how to call that function
Number()
new Number()
Date()
new Date()
After ES6, introduce arrow function and class
class: you can only use it with construction
arrow function: you can only use it with instruction sequence
class A {}
new A() // OK
A() // Error
const a = () => {}
a() // OK
new a() // Error
So now, you should know that arrow function has nothing to do with all the things which related to OOP, such as new, this, prototype
console.log(a.prototype) // undefined