[Javascript] Working with Static Properties on a Class

标签：sel   less   obj   tac   over   console   abi   return   sso   

Classes are syntactic sugar over functions and functions are also referred to as "callable" objects. So it is possible to treat a function like an object and give them key / value properties like objects. The static keyword gives us the ability to assign a key / value property to a class itself, not an instance of that class. This lesson will walk you through using the static keyword and even show how to replicate it with regular functions.

class Retangle{
  static callRectangle(){
    return ‘hello world‘
  }
}

const myShape = new Rectangle() 
console.log(myShape.callRectangle) // error, you cannot call static prop on instance

But static prop can be called from child class:

function Rectangle(){
}

Rectangle.callRectangle = function(){
  return ‘hello world‘
}
class Square extends Rectangle {
  static whoAmI(){
    return "Hello, all " + super.callRectangle()
  }
}

console.log(Square.whoAmI()) //Hello, all hello world

[Javascript] Working with Static Properties on a Class

标签：sel   less   obj   tac   over   console   abi   return   sso   

原文地址：https://www.cnblogs.com/Answer1215/p/12003897.html