The DOM can be a bit tricky when it comes to typing. You never really know exactly what you're going to get, so you have to educate your codebase into what you know you're using. This is done using Type Assertion where TypeScript types know they're a…
JavaScript过去一直被当作一种玩具语言存在,直到2005年以后,这门语言又开始活跃并可以说是火爆,而且随着浏览器版本的不断升级和完善,各种DOM之间的兼容性已经渐渐的被各种技术解决了,比如经典的jQuery,JavaScript版本也在快速发展和完善.现如今,Web世界越来越让人摸不着边际,JSON.AJAX.HTML5.Sliverlight.Node.js.PhoneGap几乎都可以见到JavaScript忙碌的身影.不过渐渐的有经验的用户会发现JavaScript语言本身的局限性导…
1.JavaScript 添加DOM Element 执行效率比较: 抄自:http://wildbit.com/blog/2006/11/21/javascript-optimization-adding-dom-elements-to-document JavaScript optimization: Adding DOM elements to document Scenario: you're developing rich Web application and you need to…
We’ll often need to access the same DOM elements multiple times in one test. Your first instinct might be to use cy.getand assign the result to a variable for reuse. This might appear to work fine at first, but can lead to trouble. Everything in Cypr…
Change is good, but creating from scratch is even better. This lesson shows you how to create DOM elements from D3 and insert them into your document as needed. You’ll officially be on your way to creating data visualizations! d3.select('.title') .in…
Once you can get hold of DOM elements you’re ready to start changing them. Whether it’s changing colors, labels, or even link destinations, this lesson demonstrates the process and patterns for updating the DOM using D3’s powerful APIs. // you will s…
Before you can create dazzling data driven documents, you need to know how D3 accesses the DOM. This lesson will show you the ins and outs of accessing existing DOM elements with D3. var div = d3.select('div'); console.log(div.nodes()); var divLinks…
一.ReactDOM 1.1 render() ReactDOM.render(element,container,[callback]) 在container中渲染一个React元素,然后返回组件一个引用(对于stateless组件,返回null).如果React元素已经加入到了container中,再次执行上面的方法会执行更新操作,只在必要时更新DOM来反映最新的React元素.如果提供可选的回调函数,则该callback会在组件渲染或者更新完后执行. 注意: ReactDOM.render…
我的electron教程系列 electron教程(一): electron的安装和项目的创建 electron教程(番外篇一): 开发环境及插件, VSCode调试, ESLint + Google JavaScript Style Guide代码规范 electron教程(番外篇二): 使用TypeScript版本的electron, VSCode调试TypeScript, TS版本的ESLint electron教程(二): http服务器, ws服务器, 子进程管理 electron教程…
11.TypeScript完全解读-类型推论和兼容性 在一些时候省略指令,ts会帮我们推断出省略的类型的地方适合的类型,通过学习ts的类型推论了解ts的推论规则 类型兼容性就是为了适应js灵活的特点,从而在一些情况下只要兼容的类型即可通过检测 创建文件并在index.ts中引入 类型推论 这里定义的name没有给他制定是什么类型的值,赋值一个字符串,ts就会给我们推断出name可能是想要一个字符串的类型 当我们再给这个name赋值一个数值类型就会报错 了. 多类型联合 我们不制定类型,ts会自动…