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Explanation and application of classes and objects in ES6

零下一度

Jun 25, 2017 am 09:26 AM

Thirteenstudyobjectseries

1. Basic definition and generated examples

{  // 基本定义和生成实例  class Parent{
    constructor(name='mukewang'){//构造器，初始化一些参数      this.name=name;
    }
  }
  let v_parent=new Parent('v');
  console.log('构造函数和实例',v_parent);
}

2. Inheritance (via extends Direct subclasses inherit parent classes)

{  // 继承  class Parent{
    constructor(name='mukewang'){      this.name=name;
    }
  }

  class Child extends Parent{

  }

  console.log('继承',new Child());
}

　Inheritance passes its own parameters (note: you can use super() to use your own attributes, and super must be placed First line)

{  // 继承传递参数  class Parent{
    constructor(name='mukewang'){      this.name=name;
    }
  }

  class Child extends Parent{
    constructor(name='child'){
      super(name);      this.type='child';
    }
  }

  console.log('继承传递参数',new Child('hello'));
}

　Getters and setters in the class

{  // getter,setter  class Parent{
    constructor(name='mukewang'){      this.name=name;
    }
　　//注意下面的longName是属性而不是方法
    get longName(){      return 'mk'+this.name
    }

    set longName(value){      this.name=value;
    }
  }

  let v=new Parent();
  console.log('getter',v.longName);
  v.longName='hello';
  console.log('setter',v.longName);
}

　Static methods and static properties

{  // 静态方法 使用static声明 注意：静态方法只能通过类来调用，而不能通过类的实例进行调用，相当于es5中的私有方法  class Parent{
    constructor(name='mukewang'){      this.name=name;
    }

    static tell(){
      console.log('tell');
    }
  }

  Parent.tell();

}

{  // 静态属性 直接类名通过.来声明一个静态属性  class Parent{
    constructor(name='mukewang'){      this.name=name;
    }

    static tell(){
      console.log('tell');
    }
  }

  Parent.type='test';

  console.log('静态属性',Parent.type);


}

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