It always discourages me...
It exasperates me to hear that frontend development is a mess, especially the statement that JavaScript "accepts anything" and can be written in any way without affecting the final result.
Actually, it is not entirely false. It is true that JavaScript allows multiple approaches to achieve the same goal.
The problem lies in the lack of design patterns as well defined as in the backend. On the frontend, best practices are dispersed, generating diversity of opinion and lack of uniformity. This dispersion makes development and understanding difficult, especially for beginners. Even whoever writes this has his own opinions.
The key point…
Beyond the frustration, I want to emphasize that the lack of evidence of good practices does not mean that they do not exist. It is essential to seek knowledge and apply at least the basics of design patterns. In JavaScript, there are many resources with established implementations and patterns. It just takes time to read and understand its purpose and proper use. Example: Mozilla Documentation for JavaScript.
A practical example…
The following code comes from a real project in production. While it works correctly, its implementation could be improved in readability and performance.
We will adjust some parts to align with the recommendations in the JavaScript documentation, using more efficient methods and functions. We will focus on a basic concept: manipulation of arrays and objects. The code is simplified for educational purposes.
Let's start with an object, representing data received from a backend API:
const storesList = [{ activeStories: [ { name: 'Starbucks', code: 1 }, { name: 'Duck Duck Coffe', code: 2 } ], inactiveStories: [ { name: 'Mac Coffe', code: 3 } ] }]
We need to add a "label" field with the prefix "Opened" followed by the store name.
Let's first look at a "less ideal" implementation, which doesn't use the best JavaScript tools:
storesList.reduce((previous, current) => { current.activeStories.forEach(store => { previous.push({ ...store, label: `Opened ${store.name}` }) }) return previous }, []) // resultado: [ { "name": "Starbucks", "code": 1, "label": "Opened Starbucks" }, { "name": "Duck Duck Coffe", "code": 2, "label": "Opened Duck Duck Coffe" } ]
We look at .reduce
, .forEach
and .push
, just to reconstruct a list. The lack of use of .flatMap
and .map
is evident. The syntax is confusing and verbose.
Let's look at an improved implementation:
storesList.flatMap((item) => { return item.activeStories }).map((item) => { return { ...item, label: `Opened ${item.name}` } })
Simpler, right?
.flatMap
"flattens" the array of objects to a single level:
[ { "name": "Starbucks", "code": 1 }, { "name": "Duck Duck Coffe", "code": 2 } ]
Then, .map
"remaps" the array, adding the "label" property:
[ { "name": "Starbucks", "code": 1, "label": "Opened Starbucks" }, { "name": "Duck Duck Coffe", "code": 2, "label": "Opened Duck Duck Coffe" } ]
Conclusion…
JavaScript offers the tools to write quality code. The important thing is to study it and apply the concepts correctly, not just program for the sake of programming.
Reading recommendations:
- [PT-BR] - https://www.php.cn/link/729404b28f3bd32761c667a668453f4c
- [EN] - https://www.php.cn/link/f5c80b20fdee4e645ff315a56f12a716
The above is the detailed content of Why is JavaScript not a mess?. For more information, please follow other related articles on the PHP Chinese website!

JavaScript is widely used in websites, mobile applications, desktop applications and server-side programming. 1) In website development, JavaScript operates DOM together with HTML and CSS to achieve dynamic effects and supports frameworks such as jQuery and React. 2) Through ReactNative and Ionic, JavaScript is used to develop cross-platform mobile applications. 3) The Electron framework enables JavaScript to build desktop applications. 4) Node.js allows JavaScript to run on the server side and supports high concurrent requests.

Python is more suitable for data science and automation, while JavaScript is more suitable for front-end and full-stack development. 1. Python performs well in data science and machine learning, using libraries such as NumPy and Pandas for data processing and modeling. 2. Python is concise and efficient in automation and scripting. 3. JavaScript is indispensable in front-end development and is used to build dynamic web pages and single-page applications. 4. JavaScript plays a role in back-end development through Node.js and supports full-stack development.

C and C play a vital role in the JavaScript engine, mainly used to implement interpreters and JIT compilers. 1) C is used to parse JavaScript source code and generate an abstract syntax tree. 2) C is responsible for generating and executing bytecode. 3) C implements the JIT compiler, optimizes and compiles hot-spot code at runtime, and significantly improves the execution efficiency of JavaScript.

JavaScript's application in the real world includes front-end and back-end development. 1) Display front-end applications by building a TODO list application, involving DOM operations and event processing. 2) Build RESTfulAPI through Node.js and Express to demonstrate back-end applications.

The main uses of JavaScript in web development include client interaction, form verification and asynchronous communication. 1) Dynamic content update and user interaction through DOM operations; 2) Client verification is carried out before the user submits data to improve the user experience; 3) Refreshless communication with the server is achieved through AJAX technology.

Understanding how JavaScript engine works internally is important to developers because it helps write more efficient code and understand performance bottlenecks and optimization strategies. 1) The engine's workflow includes three stages: parsing, compiling and execution; 2) During the execution process, the engine will perform dynamic optimization, such as inline cache and hidden classes; 3) Best practices include avoiding global variables, optimizing loops, using const and lets, and avoiding excessive use of closures.

Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.

Python and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.


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

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.

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.