September 2022
Intermediate to advanced
585 pages
8h 17m
Chinese
Content preview from JavaScript 经典实例：第三版
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类
｜
221
8.7
使用静态方法创建对象
8.7.1
问题
你想通过一个方法生成配置好的对象，希望借此绕过
JavaScript
只能有一个构造函
数的限制。
8.7.2
方案
在类中添加一个静态方法，创建并返回你想要的对象。下述示例中的
Book
类，既可
以通过构造函数创建实例，也可以使用静态方法
Book.createSequel()
创建实例。
class
Book {
constructor(title, firstName, lastName) {
this
.title = title;
this
.firstName = firstName;
this
.lastName = lastName;
}
static
createSequel(prevBook, title) {
return new
Book(title, prevBook.firstName, prevBook.lastName);
}
}
这个静态方法的使用方式如下所示。
//
使用常规的构造函数创建一个
Book
对象
const
book =
new
Book('Good Design', 'Polly', 'Morfissim');
//
使用静态方法创建一个续作
const
sequel = Book.createSequel(book, 'Even Gooder Design');
console.log(sequel);
222
｜
第
8
章
8.7.3
讨论
使用静态方法可以实现不同类型的创建型模式（
creational pattern ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.