实践一些js中的prototype, proto, constructor

Posted 2020-07-02

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<!DOCTYPE html>
<html>
<head>
    <title>ExtJs</title>
    	<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
  		<link rel="stylesheet" type="text/css" href="ExtJs/packages/ext-theme-crisp/build/resources/ext-theme-crisp-all.css">
      <script type="text/javascript" src="ExtJs/ext-all.js"></script>
      <script type="text/javascript" src="ExtJs/bootstrap.js"></script>
      <script type="text/javascript" src="ExtJs/packages/ext-theme-crisp/build/ext-theme-crisp.js"></script>
</head>
<body>
<script type="text/javascript">
  function Person(){
    this.name = ‘hanzichi‘;
    this.age = 10;
  }
  var num = 0;
  for (var i in Person.prototype)
    num++;
  console.log(num);

  Person.prototype.show = function(){
    console.log(this.name);
  };
  Person.prototype.sex = ‘male‘;

  var a = new Person();
  console.log(a.sex);
  a.show();
  console.log(a.__proto__ === Person.prototype);
  console.log(a.constructor === Person);
  console.log(Person.prototype.constructor === Person);

  console.log(Person.prototype);
  console.log(a);

  console.log(‘string‘.constructor);
  console.log(new String(‘string‘).constructor);
  console.log(/hello/.constructor);
  console.log([1,2,3].constructor);
  function A() {}
  var a = new A()
  console.log(a.constructor);

  function Book(name){
    this.name = name;
  };
  Book.prototype.getName = function(){
    return this.name;
  };
  Book.prototype = {
    //constructor: Book,
    getPName: function(){
      return this.name;
    }
  };
  Book.prototype.constructor = Book;
  var b = new Book("ON THE WAY");

  console.log(b.constructor === Book);
  console.log(Book.prototype.constructor === Book);
  console.log(b.constructor.prototype.constructor == Book);
</script>
<body>
  <div id="tpl-table">
    <div>员工信息</div>
  </div>
</body>
</html>

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