javascript继承(call方法)机制的两种实现

Posted 2020-11-01

1. 内部实现：

   function ClassA(sColor) {
   this.color = sColor
   this.sayColor = function () {
       console.log(this.color)
   }
   }
   function ClassB(sName) {
   this.name = sName
   this.sayName = function () {
       console.log(this.name)
   }
   }
   function ClassC(sColor, sName) {
   ClassA.call(this,sColor)
   ClassB.call(this,sName)
   }
   var objA = new ClassA("blue")
   var objC = new ClassC("red", "John")
   objA.sayColor()
   objC.sayColor()
   objC.sayName()

2. 外部实现：

   function ClassA(sColor) {
   this.color = sColor
   this.sayColor = function () {
       console.log(this.color)
   }
   }
   function ClassB(sName) {
   this.name = sName
   this.sayName = function () {
       console.log(this.name)
   }
   }
   function ClassC(sColor, sName) {
   }
   var objA = new ClassA("blue")
   var objC = new ClassC()
   ClassA.call(objC,‘red‘)
   ClassB.call(objC,‘John‘)
   objA.sayColor()
   objC.sayColor()
   objC.sayName()

3. 输出：

   blue
   red
   John