<script type="text/javascript">

var Book = function(newIsbn, newTitle, newAuthor) { // implements Publication

  // 私有属性

  var isbn, title, author;

  // 私有方法

  function checkIsbn(isbn) {

    if(isbn == undefined || typeof isbn != 'string') {

      return false;

    }

    return true; // All tests passed.

  }  

  // 特权方法

  this.getIsbn = function() {

    return isbn;

  };

  this.setIsbn = function(newIsbn) {

    if(!checkIsbn(newIsbn)) throw new Error('Book: Invalid ISBN.');

    isbn = newIsbn;

  };

  this.getTitle = function() {

    return title;

  };

  this.setTitle = function(newTitle) {

    title = newTitle || 'No title specified';

  };

  this.getAuthor = function() {

    return author;

  };

  this.setAuthor = function(newAuthor) {

    author = newAuthor || 'No author specified';

  };

  // 构造代码

  this.setIsbn(newIsbn);

  this.setTitle(newTitle);

  this.setAuthor(newAuthor);

};

// Public, non-privileged methods.

Book.prototype = {

  display: function() {

    alert("isbn:"+this.getIsbn()+" title:"+this.getTitle()+" author:"+this.getAuthor());

  }

};

//var theHobbit = new Book(123, '', 'J. R. R. Tolkein'); // 非字符串抛出异常

var theHobbit = new Book('1990-78sd-1092', '', 'J. R. R. Tolkein');

theHobbit.display(); // Outputs the data by creating and populating an HTML element.

</script>