prototype属性可以将属性和方法添加到任何对象(Number, Boolean, String 和Date等)。
注:原型(Prototype)是一个全局的属性,它可以使用在几乎所有的对象。
语法
object.prototype.name = value
实例:
这里有一个例子展示了如何使用原型(prototype)属性的属性添加到对象:
<html> <head> <title>User-defined objects</title> <script type="text/javascript"> function book(title, author){ this.title = title this.author = author } </script> </head> <body> <script type="text/javascript"> var myBook = new book("Perl", "Mohtashim") book.prototype.price = null myBook.price = 100 document.write("Book title is : " + myBook.title + "<br>") document.write("Book author is : " + myBook.author + "<br>") document.write("Book price is : " + myBook.price + "<br>") </script> </body> </html>
这将产生以下结果:
Book title is : Perl Book author is : Mohtashim Book price is : 100
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