JavaScript is a widely used programming language that can be used along with HTML and CSS to build dynamic websites and applications. In JavaScript, there are many different ways of writing to achieve the same goal. Below we’ll explore some different ways to write JavaScript and their pros and cons.
- Original JavaScript writing method
This is the earliest JavaScript writing method, which uses document objects to build web pages. In this way of writing, JavaScript code is usually embedded directly in the HTML file. For example:
<!DOCTYPE html>
<html>
<head>
<title>My Website</title>
<script type="text/javascript">
var message = "Hello, World!";
document.write(message);
</script>
</head>
<body>
</body>
</html>This writing method is easy to learn and understand, but it has some shortcomings. First, it makes HTML files cluttered and difficult to manage. Secondly, if you have multiple JavaScript code blocks, you need to define all variables and functions in each code block. Finally, this approach is not safe as it is vulnerable to cross-site scripting attacks.
- Declarative JavaScript writing method
Another way of writing JavaScript is declarative JavaScript writing, which uses external script files to store code. To use this writing method, you can include a script element in the HTML file and specify the src attribute. For example:
<!DOCTYPE html>
<html>
<head>
<title>My Website</title>
<script src="scripts/my_script.js"></script>
</head>
<body>
</body>
</html>In the my_script.js file, you can write all JavaScript code. This way of writing is easier to manage and maintain because it allows the code to be separated and organized into different files. Additionally, it allows the same code to be reused across multiple pages. However, this way of writing still requires variables and functions to be defined in the global namespace, which is prone to naming conflicts.
- Modular JavaScript writing method
Modular JavaScript writing method is a more advanced writing method that uses JavaScript modules to organize and encapsulate code. A module is a closed unit of variables, functions, and classes that are visible only inside the module. Modules can be defined in files and communicate with other modules through import and export statements. For example:
// 模块 my_module.js
let message = "Hello, World!";
function showMessage() {
console.log(message);
}
export default showMessage;// 模块 main.js import showMessage from "./my_module.js"; showMessage();
This way of writing makes the code more modular and reusable. It improves code security by hiding implementation details and reduces the possibility of naming conflicts. Furthermore, the idea behind modularity is also a core concept in modern web frameworks.
- Functional JavaScript writing
Functional JavaScript writing is a paradigm that emphasizes pure functions, that is, those that do not introduce side effects and only calculate return values based on their inputs function. This way of writing emphasizes function composition and piping to make it easier to write high-quality, testable, and understandable code. For example:
const add = x => y => x + y;
const multiply = x => y => x * y;
const calculate = (x, y) => {
const addResult = add(x)(y);
const multiplyResult = multiply(x)(y);
return addResult + multiplyResult;
};
console.log(calculate(2, 3)); // 11This way of writing can improve the readability and maintainability of the code. It's also easier to unit test since each function is independent.
Conclusion
There are many different ways to write JavaScript to achieve the same goal. Different writing methods have different advantages and disadvantages, and you can choose the appropriate method according to the specific situation. However, modularity and functional programming thinking are core concepts in modern JavaScript development and are worth learning and using in depth.
The above is the detailed content of Different ways of writing javascript. For more information, please follow other related articles on the PHP Chinese website!
What are the limitations of React?May 02, 2025 am 12:26 AMReact'slimitationsinclude:1)asteeplearningcurveduetoitsvastecosystem,2)SEOchallengeswithclient-siderendering,3)potentialperformanceissuesinlargeapplications,4)complexstatemanagementasappsgrow,and5)theneedtokeepupwithitsrapidevolution.Thesefactorsshou
React's Learning Curve: Challenges for New DevelopersMay 02, 2025 am 12:24 AMReactischallengingforbeginnersduetoitssteeplearningcurveandparadigmshifttocomponent-basedarchitecture.1)Startwithofficialdocumentationforasolidfoundation.2)UnderstandJSXandhowtoembedJavaScriptwithinit.3)Learntousefunctionalcomponentswithhooksforstate
Generating Stable and Unique Keys for Dynamic Lists in ReactMay 02, 2025 am 12:22 AMThecorechallengeingeneratingstableanduniquekeysfordynamiclistsinReactisensuringconsistentidentifiersacrossre-rendersforefficientDOMupdates.1)Usenaturalkeyswhenpossible,astheyarereliableifuniqueandstable.2)Generatesynthetickeysbasedonmultipleattribute
JavaScript Fatigue: Staying Current with React and Its ToolsMay 02, 2025 am 12:19 AMJavaScriptfatigueinReactismanageablewithstrategieslikejust-in-timelearningandcuratedinformationsources.1)Learnwhatyouneedwhenyouneedit,focusingonprojectrelevance.2)FollowkeyblogsliketheofficialReactblogandengagewithcommunitieslikeReactifluxonDiscordt
Testing Components That Use the useState() HookMay 02, 2025 am 12:13 AMTotestReactcomponentsusingtheuseStatehook,useJestandReactTestingLibrarytosimulateinteractionsandverifystatechangesintheUI.1)Renderthecomponentandcheckinitialstate.2)Simulateuserinteractionslikeclicksorformsubmissions.3)Verifytheupdatedstatereflectsin
Keys in React: A Deep Dive into Performance Optimization TechniquesMay 01, 2025 am 12:25 AMKeysinReactarecrucialforoptimizingperformancebyaidinginefficientlistupdates.1)Usekeystoidentifyandtracklistelements.2)Avoidusingarrayindicesaskeystopreventperformanceissues.3)Choosestableidentifierslikeitem.idtomaintaincomponentstateandimproveperform
What are keys in React?May 01, 2025 am 12:25 AMReactkeysareuniqueidentifiersusedwhenrenderingliststoimprovereconciliationefficiency.1)TheyhelpReacttrackchangesinlistitems,2)usingstableanduniqueidentifierslikeitemIDsisrecommended,3)avoidusingarrayindicesaskeystopreventissueswithreordering,and4)ens
The Importance of Unique Keys in React: Avoiding Common PitfallsMay 01, 2025 am 12:19 AMUniquekeysarecrucialinReactforoptimizingrenderingandmaintainingcomponentstateintegrity.1)Useanaturaluniqueidentifierfromyourdataifavailable.2)Ifnonaturalidentifierexists,generateauniquekeyusingalibrarylikeuuid.3)Avoidusingarrayindicesaskeys,especiall
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.
WebStorm Mac version
Useful JavaScript development tools
SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.
SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.
Dreamweaver Mac version
Visual web development tools
