JSOOP class

• A simple example 

class Circle {
  constructor (radius) {
    this.radius = radius
    this.move = function() {}
  }
  draw() {
    console.log('draw')
  }
}

const c = new Circle(1)

 class is essentially a function, _classCallCheck to ensure the use of new

•  The difference between function and expression

Function declarations are sticky, the expression does not top

sayHello()
sayHi()
function sayHello() {
  console.log('Hello')
}
const sayHi = function(){
  console.log('Hi')
}

 

 Class expressions and statements are not top class,

const c = new Circle()
class Circle {
}
const Square = class {}