Web Front-endJS TutorialHigh Performance JavaScript (High Performance JavaScript) reading note analysis_javascript skillsHigh Performance JavaScript (High Performance JavaScript) reading note analysis_javascript skills
The browser’s JavaScript engine is a compiler layer optimization;
When the browser executes JavaScript code, it cannot do anything else at the same time ( Single process), which means that every time the <script> tag appears, it will overbearingly let the page and other scripts be parsed and executed (each file must wait until the previous file is downloaded and executed before it starts downloading), so the JS and CSS is used to render the page, and JS for interactive behaviors (almost all) is placed at the bottom of <body>; <BR> all major browsers allow parallel downloading of JS. <BR>Reducing the number of external link scripts will improve performance (merging JS) <BR>Any website can use a URL that combines the specified files to obtain any number of files. <BR>The defer attribute can defer scripts (only supported by IE4 and FF3.5) <BR><STRONG>Chapter 2: Data Access <br><br>There are four basic data access locations in JavaScript: Direct quantities, variables, array elements (indexed by numbers), object members (indexed by character beds). <BR>Accessing direct quantities and local variables is the fastest. On the contrary, accessing array elements and object members is relatively slow. <BR>The deeper a property or method is in the prototype chain, the slower it is to access it. <BR>Generally speaking, JavaScript performance can be improved by saving commonly used objects, array elements, and cross-variables in local variables. <BR><STRONG>Chapter 3: DOM Programming <br><br>DOM operations are faster in webkit-based browsers, while other browsers execute innerHTML faster. <BR>Accessing and manipulating DOM is an important part of modern WEB applications. But every time you cross the bridge linking the two islands of ECMAScript and DOM, you will be charged a 'bridge toll'. <BR>Be aware of re-entry and rearrangement. <BR>In IE:hover will reduce the response speed. <BR><STRONG>Chapter 4: Algorithms and Process Control <BR><BR>Avoid using for-in loops unless you need to traverse an object with a number of attributes. <BR>Learn about stack overflow errors. <BR><STRONG>Chapter 5: Strings and Regular Expressions <br><br>Backtracking is both a fundamental component of regular expression matching functionality and a source of regular expression inefficiency. <BR><STRONG>Chapter 6: Responsive User Interface <br><br>No JavaScript task should take more than 100 milliseconds to execute. <BR>Web workers are a feature supported by new browsers. <BR>No JavaScript code is important enough to affect the user experience. <BR><STRONG>Chapter 7: Ajax <br><br>JSON is a lightweight data format with fast parsing speed. <BR>Reduce the number of requests by merging JS and CSS, as well as IMG. <BR>Shorten page loading time. After the main content of the page is loaded, use Ajax to obtain those secondary files. <BR><STRONG>Chapter 8: Programming Practice <br><br>Most of the time, there is no need to use eval() and Function(), so it is best to avoid using them. As for setTimeout() and setInterval(), it is recommended to pass in a function instead of a string as the first parameter. <BR>There are many ways to create objects and arrays in JavaScript, but using object and array literals is the fastest way (the more object properties and array items there are, the more obvious the benefits of using literals). <BR>Don’t duplicate work: lazy loading; conditional preloading. <BR>Use native methods more because they are faster. <BR><STRONG>Chapter 9: Build and deploy high-performance JavaScript applications <br><br>PV (page view) is page views or clicks. <BR>Reduce the number of HTTP requests required to render a page, especially for those users visiting the site for the first time. <BR>JavaScript compression. <BR>JavaScript caching. <BR>Using Content Delivery Network (CDN) <BR>Chapter 10 mainly introduces tools: such as firebug, YSlow, and some performance analysis.</script>
JavaScript Engines: Comparing ImplementationsApr 13, 2025 am 12:05 AMDifferent JavaScript engines have different effects when parsing and executing JavaScript code, because the implementation principles and optimization strategies of each engine differ. 1. Lexical analysis: convert source code into lexical unit. 2. Grammar analysis: Generate an abstract syntax tree. 3. Optimization and compilation: Generate machine code through the JIT compiler. 4. Execute: Run the machine code. V8 engine optimizes through instant compilation and hidden class, SpiderMonkey uses a type inference system, resulting in different performance performance on the same code.
Beyond the Browser: JavaScript in the Real WorldApr 12, 2025 am 12:06 AMJavaScript's applications in the real world include server-side programming, mobile application development and Internet of Things control: 1. Server-side programming is realized through Node.js, suitable for high concurrent request processing. 2. Mobile application development is carried out through ReactNative and supports cross-platform deployment. 3. Used for IoT device control through Johnny-Five library, suitable for hardware interaction.
Building a Multi-Tenant SaaS Application with Next.js (Backend Integration)Apr 11, 2025 am 08:23 AMI built a functional multi-tenant SaaS application (an EdTech app) with your everyday tech tool and you can do the same. First, what’s a multi-tenant SaaS application? Multi-tenant SaaS applications let you serve multiple customers from a sing
How to Build a Multi-Tenant SaaS Application with Next.js (Frontend Integration)Apr 11, 2025 am 08:22 AMThis article demonstrates frontend integration with a backend secured by Permit, building a functional EdTech SaaS application using Next.js. The frontend fetches user permissions to control UI visibility and ensures API requests adhere to role-base
JavaScript: Exploring the Versatility of a Web LanguageApr 11, 2025 am 12:01 AMJavaScript is the core language of modern web development and is widely used for its diversity and flexibility. 1) Front-end development: build dynamic web pages and single-page applications through DOM operations and modern frameworks (such as React, Vue.js, Angular). 2) Server-side development: Node.js uses a non-blocking I/O model to handle high concurrency and real-time applications. 3) Mobile and desktop application development: cross-platform development is realized through ReactNative and Electron to improve development efficiency.
The Evolution of JavaScript: Current Trends and Future ProspectsApr 10, 2025 am 09:33 AMThe latest trends in JavaScript include the rise of TypeScript, the popularity of modern frameworks and libraries, and the application of WebAssembly. Future prospects cover more powerful type systems, the development of server-side JavaScript, the expansion of artificial intelligence and machine learning, and the potential of IoT and edge computing.
Demystifying JavaScript: What It Does and Why It MattersApr 09, 2025 am 12:07 AMJavaScript is the cornerstone of modern web development, and its main functions include event-driven programming, dynamic content generation and asynchronous programming. 1) Event-driven programming allows web pages to change dynamically according to user operations. 2) Dynamic content generation allows page content to be adjusted according to conditions. 3) Asynchronous programming ensures that the user interface is not blocked. JavaScript is widely used in web interaction, single-page application and server-side development, greatly improving the flexibility of user experience and cross-platform development.
Is Python or JavaScript better?Apr 06, 2025 am 12:14 AMPython is more suitable for data science and machine learning, while JavaScript is more suitable for front-end and full-stack development. 1. Python is known for its concise syntax and rich library ecosystem, and is suitable for data analysis and web development. 2. JavaScript is the core of front-end development. Node.js supports server-side programming and is suitable for full-stack development.
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