JavaScript继承实现方式一览

继承 类继承 类抄写 function  parent(){      this .x = 10 ; } function  child(){      var  parentObj = new  parent();      for ( var  p  in  parentObj) this [p] = parentObj[p]; } var  childObj = new  child(); alert(childObj.x);   类冒充   function  parent(){      this .x = 10 ; } function  child(){      this .parent = parent;      this .parent();      delete   this .parent; } var  childObj = new  child(); alert(childObj.x);   function  parent(){      this .x = 10 ; } function  child(){     parent.call( this ); } var  childObj = new  child(); alert(childObj.x);   原型抄写   function  parent(){ } parent.prototype.x = 1 ; function  child(){ } for ( var  p  in  parent.prototype)child.prototype[p] = parent.prototype[p]; child.prototype.y = 2 ; var  childObj = new  child(); alert(childObj.x);     元类继承 function  parent(string){      var  child = new  Function( " this.x=10; " + string);      return  child; } var  child = new  parent( " this.y=20; " ); var  childObj = new  child(); alert(childObj.y);   原型继承 引用型原型继承 function  parent(){      this .x = 10 ; } function  child(){ } child.prototype = new  parent(); var  childObj = new  child(); alert(childObj.x);   复制型原型继承 function  parent(){      this .x = 10 ; } function  child(){      var  ret = new  parent();     ret.y = 20 ;      return  ret; } var  childObj = new  child(); alert(childObj.x);