对象方法链化

come from javascriptcookbook

function book (title, author) {
    this.getTitle = function () {
        return 'title: " + title;
    }

    this.replaceTitle = function (newTitle) {
        var oldTitle = title;
        title = newTitle;
    }
}

function newbook (
    book.apply (this, arguments)

    this.replaceTitle = function (newTitle) {
        this.replaceTitle(newAuthor)
        return this;  //支持方法链化所必需的
    }
}

使用call()将两个对象连接起来。如果想在两个对象之间传递参数列表，则使用apply()。