In this lesson, we’ll look at the propPath utility function. We’ll ask for a property multiple levels deep in an object and get back a Maybe. We’ll get a Just when the property exists at our path and a Nothing if any part of the path is undefined. co…
In this lesson, we’ll use a Maybe to safely operate on properties of an object that could be undefined. We’ll use our initial code as the basis for a prop utility function that can be reused with different objects and various property names. Instead…
public class Employee { public Employee() { this.Insurance = new Insurance(); } // Perhaps another constructor for the name? public Employee(string name) : this() { this.Name = name; } public string Name { get; set; } public Insurance Insurance { get…
Sometimes, we run into situations where we end up with a Maybe within the context of another Maybe. Nested structures like this can get really confusing to work with. In this lesson, we’ll look at an example of this and see how chaincan help us out b…
javascript nested object merge deep copy Object reference type function namespace(oNamespace, sPackage) { // deep copy let res = oNamespace; const arr = sPackage.split("."); //  ["a", "b", "c", "d"] const…
For example, in React application, we have initial state; const data = { nextId: 4, todoFilter: 'SHOW_ALL', todos: [ { id: 1, title: 'Hug Unicorn', completed: false }, { id: 2, title: 'Mess with Texas', completed: false }, { id: 3, title: 'Do Laundry…
1.做一个实验,引出来为什么需要nested object 冗余数据方式的来建模,其实用的就是object类型,我们这里又要引入一种新的object类型,nested object类型 博客,评论,做的这种数据模型 PUT /website/blogs/6 { "title": "花无缺发表的一篇帖子", "content": "我是花无缺,大家要不要考虑一下投资房产和买股票的事情啊...", "tags"…
Avoid replacing instance root $data. Use nested data properties instead. 翻译 避免替换实例根$data.请改用嵌套数据属性 错误的代码 const demoData={ name:"小明", age:19 } this.$data=demoData; //此种直接赋值即会导致警告产生(对象的拷贝默认是深拷贝即引用) 产生原因 最新的Vue已经不允许这样直接对跟实例$data进行赋值 解决方案 使用 Object.…
上一篇(JavaScript中你所不知道的Object(一))说到,Object对象有大量的内部属性,而其中多数和外部属性的操作有关.最后留了个悬念,就是Boolean.Date.Number.String.Function等有更多的内部属性,而它们分别是什么呢? 这些内部属性不能像Object的内部属性一样一言以蔽之,因为它们各有各的用处和特点.其中核心的部分自然是最特殊的对象,Function对象.我们先从简单的开始: [[PrimitiveValue]]: 值的类型是基础数据类型.所以所有…
[流程描述] 登录126邮箱,退出 [代码] #coding=utf-8 from selenium import webdriver driver = webdriver.Firefox() #driver = webdriver.Ie() driver.implicitly_wait(10) driver.get("https://mail.126.com/") #切换到frame driver.switch_to.frame("x-URS-iframe") #…