JSOOP 多态 及其应用场景

• 多态实现及其应用 

function extend(Child, Parent) {
  Child.prototype = Object.create(Parent.prototype)
  Child.prototype.constructor = Child
}

function Shape(color) {
  this.color = color
}

Shape.prototype.duplicate = function() {
  console.log('duplicate')
}

function Circle(radius, color) {
  Shape.call(this, color)
  this.radius = radius
}

extend(Circle, Shape)
Circle.prototype.draw = function() {
  console.log('draw')
}

Circle.prototype.duplicate = function() {
  console.log('circle duplicate')
}
function Square() {

}
extend(Square, Shape)
Square.prototype.duplicate = function() {
  console.log('square duplicate')
}
const s = new Shape()
const c = new Circle(1, 'red')

const shapes = [
  new Circle(),
  new Square()
]
for (const shape of shapes) {
  shape.duplicate()
}