<code>function person(name,age){ this.name = name; this.age = age; } person.prototype.say = function(){ console.log(this.name+":"+this.age); } function superman(name,age){ person.call(this,name,age); } superman.prototype = new person(); var s = new superman('superman',29); </code>
I saw this inheritance method in a book and said it was perfect, but I don’t think so because its superman.prototype = new person();
This sentence will add the instance attributes of the parent class to the child class. On the prototype, although person.call(this, name, age);
has obtained the instance attributes of the parent class, it feels like this pollutes the prototype of the subclass. How to break it?
<code>function object(obj){ function F(){} F.prototype = obj; return new F(); } function inheritProtoType(SuperType,SubType){ var prototype = object(SuperType.prototype); prototype.constructor = SubType; SubType.prototype = prototype; } function SuperType(){ this.name = 'yuhualingfeng'; this.friends = ['David','Bob','Lucy']; } SuperType.prototype.saySuperName = function(){ console.log(this.name); }; function SubType(){ SuperType.call(this); this.age = 30; } inheritProtoType(SuperType,SubType); SubType.prototype.saySubName = function(){ console.log(this.name); }; var subType = new SubType(); </code>
<code>function person(name,age){ this.name = name; this.age = age; } person.prototype.say = function(){ console.log(this.name+":"+this.age); } function superman(name,age){ person.call(this,name,age); } superman.prototype = new person(); var s = new superman('superman',29); </code>
I saw this inheritance method in a book and said it was perfect, but I don’t think so because its superman.prototype = new person();
This sentence will add the instance attributes of the parent class to the child class. On the prototype, although person.call(this, name, age);
has obtained the instance attributes of the parent class, it feels like this pollutes the prototype of the subclass. How to break it?
<code>function object(obj){ function F(){} F.prototype = obj; return new F(); } function inheritProtoType(SuperType,SubType){ var prototype = object(SuperType.prototype); prototype.constructor = SubType; SubType.prototype = prototype; } function SuperType(){ this.name = 'yuhualingfeng'; this.friends = ['David','Bob','Lucy']; } SuperType.prototype.saySuperName = function(){ console.log(this.name); }; function SubType(){ SuperType.call(this); this.age = 30; } inheritProtoType(SuperType,SubType); SubType.prototype.saySubName = function(){ console.log(this.name); }; var subType = new SubType(); </code>
Object.create(Person.prototype);
This can be effectively solved, but please pay attention to compatibility
<code>function create(obj) { if (Object.create) { return Object.create(obj); } function f() {}; f.prototype = obj; return new f(); }</code>
Inherit person.prototype
Inherit instead of pollute