| let regex; | |
| /* 匹配特定的字符串 */ | |
| regex = /hello/; // 查找斜杠中的字符串（大小写敏感）……匹配 "hello", "hello123", "123hello123", "123hello"，但不匹配 "hell0", "Hello" | |
| regex = /hello/i; // 查找斜杠中的字符串（大小写不敏感）……匹配 "hello", "HelLo", "123HelLO" | |
| regex = /hello/g; // 全局查找斜杠中的字符串…… | |
| /* 通配符 */ | |
| regex = /h.llo/; // "." 匹配除了换行外的任何一个字符……匹配 "hello", "hallo"，但不匹配 "h\nllo" | |
| regex = /h.*llo/; // "*" 匹配任何字符零次或多次，如 "hello", "heeeeeello", "hllo", "hwarwareallo" |
| Hi All! | |
| I've recently launched a tool that wraps many of the commands here with a user interface. This desktop application is currently available for macOS. There's a roadmap outlining planned features for the near future. | |
| Feel free to request any features you'd like to see, and I'll prioritize them accordingly. | |
| One of the most important aspects of this application is that every command executed behind the scenes is displayed in a special log section. This allows you to see exactly what’s happening and learn from it. | |
| Here's the link to the repository: https://github.com/Pulimet/ADBugger | |
| App Description: | |
| ADBugger is a desktop tool designed for debugging and QA of Android devices and emulators. It simplifies testing, debugging, and performance analysis by offering device management, automated testing, log analysis, and remote control capabilities. This ensures smooth app performance across various setups. |
React Fiber is an ongoing reimplementation of React's core algorithm. It is the culmination of over two years of research by the React team.
Many of us building single-page apps today use JavaScript module bundling tools that trend towards a monolithic "bundle.js" file including the full app and vendor code for multiple routes. This means if a user lands on any arbitrary route they need to wait for a large bundle of JS to be fetched, parsed and executed before the application is fully rendered and interactive.
This is a little backwards, especially when apps are used under real-world network (3G) and device
| // getComponent is a function that returns a promise for a component | |
| // It will not be called until the first mount | |
| function asyncComponent(getComponent) { | |
| return class AsyncComponent extends React.Component { | |
| static Component = null; | |
| state = { Component: AsyncComponent.Component }; | |
| componentWillMount() { | |
| if (!this.state.Component) { | |
| getComponent().then(Component => { |
| /* eslint-disable no-console */ | |
| import _ from 'underscore'; | |
| /* | |
| Drop this mixin into a component that wastes time according to Perf.getWastedTime() to find | |
| out what state/props should be preserved. Once it says "Update avoidable!" for {state, props}, | |
| you should be able to drop in React.addons.PureRenderMixin | |
| React.createClass { | |
| mixins: [WhyDidYouUpdateMixin] |
| function mapValues(obj, fn) { | |
| return Object.keys(obj).reduce((result, key) => { | |
| result[key] = fn(obj[key], key); | |
| return result; | |
| }, {}); | |
| } | |
| function pick(obj, fn) { | |
| return Object.keys(obj).reduce((result, key) => { | |
| if (fn(obj[key])) { |
All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.
Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.
elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent