这篇文章将讲述immutable.js的基本语法和用法. 1.fromJs()  Deeply converts plain JS objects and arrays to Immutable Maps and Lists. immutable.fromJs([1,2,3]) 相当于 immutable.List([1,2,3])  把一个js数组转化为immutable的形式 查看list的大小  immutableA.size 或者  immutable.count() 判断是否是list…

为啥要用immutable.js呢.毫不夸张的说.有了immutable.js(当然也有其他实现库)..才能将react的性能发挥到极致!要是各位看官用过一段时间的react,而没有用immutable那么本文非常适合你. 1,对于react的来说,如果父组建有多个子组建 想象一下这种场景,一个父组建下面一大堆子组建.然后呢,这个父组建re-render.是不是下面的子组建都得跟着re-render.可是很多子组建里面是冤枉的啊!!很多子组建的props 和 state 然而并没有改变啊!!虽然…

不可变数据是指一旦创建就不能被修改的数据,使得应用开发更简单,允许使用函数式编程技术,比如惰性评估.Immutable JS 提供一个惰性 Sequence,允许高效的队列方法链,类似 map 和 filter ,不用创建中间代表.Immutable.js 提供持久化的列表.堆栈.Map, 以及 OrderedMap 等,最大限度地减少需要复制或缓存数据. 在线演示      源码下载 您可能感兴趣的相关文章 网站开发中很有用的 jQuery 效果[附源码] 分享35个让人惊讶的 CSS3 动画…

最近做一些复杂html常常需要在页面做一些数据处理,常常在想如果 js有list 这种数据结构多少,今天逛github时 发现有Immutable.js 这个项目https://github.com/facebook/immutable-js/ 文档地址:http://facebook.github.io/immutable-js/docs/#/ 在浏览器尝试了下发现还是不错的,起码不用自己用js写list的实现. var list=Immutable.List().asMutable(); l…

这段时间做的项目开发中用的是React+Redux+ImmutableJs+Es6开发,总结了immutable.js的相关使用姿势: Immutable Data 顾名思义是指一旦被创造后,就不可以被改变的数据.可以通过使用Immutable Data,可以让我们更容易的去处理缓存.回退.数据变化检测等问题,简化我们的开发. 我们知道 react.js很著名的就是它处理dom的做法,它是通过Virtual Dom来查看diff,然后再改动需要改动的Dom.但是有个问题当state更新时,如果数…

Learn how to create an Immutable.Map() through plain Javascript object construction and also via array tuples. console.clear(); // Can be an object var map = Immutable.Map({key: "value"}); console.log(map.get("key")); //"value&quo…

Learn how Immutable.js data structures are different from native iterable Javascript data types and why they provide an excellent foundation on which to build your application's state. Instead of them being mutable, they're always immutable, meaning…

Immutable.js offers methods to break immutable structures into subsets much like Array--for instance it has the all powerful slice()--and unlike Array it offers functional methods like take() and skip(). You get the best of both the imperative and fu…

Immutable.js provides several methods to iterate over an Immutable.Map(). These also apply to the other immutable structures found within the Immutable.js family, such as Set and List. The primary methods are map and forEach, but we will also cover f…

The Immutable.js Record() allows you to model your immutable data much like you would model data with native Javascript classes or objects. It differs from native classes because it cannot be mutated after it's creation and it always has a default va…

While Immutable.js offers .is() to confirm value equality between iterables it comes at the cost of referencing each key and value in both objects. For lightning fast equality checks, Immutable.js can produce a hash code based on an iterable's conten…

Understanding Immutable.js's Map() and List() structures will likely take you as far as you want to go with immutable programming. They have only small semantic differences between each other and the remaining structures in the Immutable.js family. S…

Immutable.js provides several conversion methods to migrate one structure to another. Each Immutable.js class contains a prefixed "to" method like Map.toList(), Map.toSet(), etc. Converting these types sometimes results in a loss of data, as we…

Immutable.js iterables offer the reduce() method, a powerful and often misunderstood functional operator on which map(), filter(), groupBy(), etc. are built. The concept is simple: reduce transforms your iterable into something else, that's all. The…

The Immutable.js Map() is analogous to a Javascript Object or Hash since it is comprised of key-value pairs. The Immutable.js List() is analogous to a Javascript Array and contains many of the same native methods. Let's compare the two and dive into…

Immutable.js offers the fromJS() method to build immutable structures from objects and array. Objects are converted into maps. Arrays are converted into lists. The fromJS() method can also take a reviver function for custom conversions.  Object to Im…

使用情境: 技术栈为:react + redux + antd (reducer中处理数据使用了immutable.js). 问题:如下图,做一个搜索功能,form表单每改变一次,都会调用一个update函数将更新的数据合并进去.在下图中,标签传递的值为{ label: ["1", "2", "3"] },在增加一个标签会传{ label: ["1", "2", "3","n&…

更好的阅读体验 更好的阅度体验 Immutable.js Immutable的优势 1. 保证不可变(每次通过Immutable.js操作的对象都会返回一个新的对象) 2. 丰富的API 3. 性能好 (通过字典树对数据结构的共享) Immutable的问题 1. 与原生JS交互不友好 (通过Immutable生成的对象在操作上与原生JS不同,如访问属性,myObj.prop1.prop2.prop3 => myImmutableMap.getIn(['prop1', 'prop2', 'pro…

immutable.js 在React.Redux中的实践以及常用API简介 学习下 这个immutable Data 是什么鬼,有什么优点,好处等等 mark :  https://yq.aliyun.com/articles/69516 1简介 2一个说明不可变的例子 3有哪些数据类型? 4几个重要的API 5fromJS() 6toJS() 7Map 8简单介绍 OrderedMap 9List 10API 11创建 12通过构造函数 Map() 13Map() 14List() 15另一…

来自一位美团大牛的分享,相信可以帮助到你. 原文链接:https://juejin.im/post/5948985ea0bb9f006bed7472?utm_source=tuicool&utm_medium=referral 前言   本文主要介绍facebook推出的一个类库immutable.js,以及如何将immutable.js集成到我们团队现有的react+redux架构的移动端项目中. 本文较长(5000字左右),建议阅读时间: 20 min 通过阅读本文,你可以学习到: 什么是i…

The key to being productive with Immutable JS is understanding how to update values that are nested. Using setIn you can place a new value directly into an existing or new path. If you need access to the previous value before setting the new one, you…

Immutable.js 实现原理 Immutable collections for JavaScript v4.0.0-rc.12 released on Oct 31, 2018 https://github.com/immutable-js/immutable-js/releases https://immutable-js.github.io/immutable-js/ 不变的数据一旦创建就无法更改,从而导致应用程序开发更加简单,无防御性复制,并能够以简单的逻辑实现高级的备忘和更改检测…

angular里面变化检测是非常频繁的发生的,如果你像下面这样写代码 <div> {{hello()}} </div> 则每次变化检测都会执行hello函数,如果hello函数十分耗时,则会出现占用CPU高的问题. 这时,推荐使用OnPush策略和immutable.js来提升angular应用的性能. OnPush策略可以阻止angular变化检测传入组件,这样每次变化检测不会进到你的组件里面来调用hello函数. 引入immutable.js的作用是为了更加方便的使用OnPus…

//Map() 原生object转Map对象 (只会转换第一层,注意和fromJS区别) immutable.Map({name:'danny', age:18}) //List() 原生array转List对象 (只会转换第一层,注意和fromJS区别) immutable.List([1,2,3,4,5]) //fromJS() 原生js转immutable对象 (深度转换,会将内部嵌套的对象和数组全部转成immutable) immutable.fromJS([1,2,3,4,5]) //…

1 使用combineReaducers 整合reducers import { combineReducers } from 'redux-immutable'; import { reducer as headerReducer } from '../common/header/store'; import { reducer as homeReducer } from '../pages/home/store'; import { reducer as detailReducer } fr…

Learn how to query an Immutable.Map() using get, getIn, has, includes, find, first and last. These are powerful operators that make finding data in an object graph pain free. has, includes, contains: //has() var map = Immutable.Map({a: '10'}); consol…

We will now look at five methods that modify an Immutable.Map(). set update delete clear merge //set() var map = Immutable.Map(); var todo = { id: +new Date(), name: "todo1", content: "learning Immutable" } map = map.set(todo.id, todo)…

1. immutable相当于 JSON.parse 和 JSON.stringify: 2.引入redux中,除了 在最外层 reducer中  import { combineReducers } from 'redux-immutable'; 涉及到修改 (1)reducer 两个文件  (2)组件 2.1 对于reducer: 首先对默认状态: import { fromJS } from 'immutable';const defaultState = fromJS({ 'requir…

Shared mutable state is the root of all evil(共享的可变状态是万恶之源) -- Pete Hunt 有人说 Immutable 可以给 React 应用带来数十倍的提升,也有人说 Immutable 的引入是近期 JavaScript 中伟大的发明,因为同期 React 太火,它的光芒被掩盖了.这些至少说明 Immutable 是很有价值的,下面我们来一探究竟. JavaScript 中的对象一般是可变的(Mutable),因为使用了引用赋值,新的对象…

Brief 一天有个朋友问我“JS中计算0.7 * 180怎么会等于125.99999999998,坑也太多了吧!”那时我猜测是二进制表示数值时发生round-off error所导致,但并不清楚具体是如何导致,并且有什么方法去规避.于是用了3周时间静下心把这个问题搞懂,在学习的过程中还发现不仅0.7 * 180==125.99999999998,还有以下的坑 1. 著名的 0.1 + 0.2 === 0.30000000000000004 2. 1000000000000000128 ===…