CSS is not repeated: How to better manage and operate CSS
CSS (cascading style sheets) is one of the most important technologies in front-end development, used for page beautification, layout and interactive effects. CSS is frequently used during the development process, but many developers will encounter one or more problems: CSS style conflicts and repeated definitions, making the code difficult to manage, maintain, and debug. CSS non-duplication has become a goal pursued by many front-end developers. This article will explore the techniques and methods.
- Use the class selector
In CSS, both the id selector and the class selector can select elements for style definition. But the id selector should only appear once in a page to uniquely identify an element. Therefore, if multiple elements need to share styles, the class selector should be used to avoid repeated definitions.
For example, we want to set the styles of multiple buttons on the page to be the same:
<button class="btn-primary">按钮1</button> <button class="btn-primary">按钮2</button> <button class="btn-primary">按钮3</button>
.btn-primary { background-color: #007bff; color: #fff; border: none; border-radius: 4px; padding: 8px 16px; cursor: pointer; }
Using the class selector can easily define the style without having to repeat the definition every time.
- Inherit styles
In CSS, child elements can inherit the style attributes of the parent element. For example, we can set the color and font of all p tags in the following way:
body { color: #333; font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; } p { /* 继承body的color和font-family */ }
In this way, we can save the trouble of setting styles in some cases, and also make the code more concise.
- Avoid nesting
In CSS, you can use nesting rules to apply the same style to related elements. For example:
.wrapper { background-color: #fafafa; padding: 16px; h1 { font-size: 28px; color: #333; } p { font-size: 14px; color: #666; } }
Here, we define a wrapper class, which contains an h1 and a p element. Nested rules make it easy to define styles for related elements. However, using nested rules can easily lead to increased selector complexity and may cause style conflicts. Therefore, abuse of nested rules should be avoided.
- Using preprocessors
Currently, the more popular CSS preprocessors include Sass, Less, Stylus, etc. They allow us to write more optimized, modular CSS code, improve code reusability, and also support advanced features such as mixins and functions.
For example, in Sass, we can define a mixin named primary to be used in multiple elements:
@mixin primary { background-color: #007bff; color: #fff; border: none; border-radius: 4px; padding: 8px 16px; cursor: pointer; } .btn-primary { @include primary; }
In this way, we can pass the @include directive Insert the primary mixer into the .btn-primary class to avoid writing the same style repeatedly.
- Use CSS modularization
CSS modularization is a newer way of writing CSS, which allows us to write more modular and reusable CSS code. It uses a method similar to JavaScript modules to define the component's style as an independent module, thereby avoiding global pollution and naming conflicts.
Some popular CSS modular frameworks include BEM (Block Element Modifier), SMACSS (Scalable and Modular Architecture for CSS), etc. By using these frameworks, we can define and manage CSS styles more conveniently.
Summary
CSS non-duplication is a very important goal for us to optimize front-end development. In actual development, we can use techniques such as class selectors, inherited styles, and avoiding nesting to avoid repeated CSS definitions. At the same time, using CSS preprocessors and modular frameworks in code can help us better manage and operate CSS. Improve code maintainability and reusability.
The above is the detailed content of css does not repeat. For more information, please follow other related articles on the PHP Chinese website!

useState()isaReacthookusedtomanagestateinfunctionalcomponents.1)Itinitializesandupdatesstate,2)shouldbecalledatthetoplevelofcomponents,3)canleadto'stalestate'ifnotusedcorrectly,and4)performancecanbeoptimizedusinguseCallbackandproperstateupdates.

Reactispopularduetoitscomponent-basedarchitecture,VirtualDOM,richecosystem,anddeclarativenature.1)Component-basedarchitectureallowsforreusableUIpieces,improvingmodularityandmaintainability.2)TheVirtualDOMenhancesperformancebyefficientlyupdatingtheUI.

TodebugReactapplicationseffectively,usethesestrategies:1)AddresspropdrillingwithContextAPIorRedux.2)HandleasynchronousoperationswithuseStateanduseEffect,usingAbortControllertopreventraceconditions.3)OptimizeperformancewithuseMemoanduseCallbacktoavoid

useState()inReactallowsstatemanagementinfunctionalcomponents.1)Itsimplifiesstatemanagement,makingcodemoreconcise.2)UsetheprevCountfunctiontoupdatestatebasedonitspreviousvalue,avoidingstalestateissues.3)UseuseMemooruseCallbackforperformanceoptimizatio

ChooseuseState()forsimple,independentstatevariables;useuseReducer()forcomplexstatelogicorwhenstatedependsonpreviousstate.1)useState()isidealforsimpleupdatesliketogglingabooleanorupdatingacounter.2)useReducer()isbetterformanagingmultiplesub-valuesorac

useState is superior to class components and other state management solutions because it simplifies state management, makes the code clearer, more readable, and is consistent with React's declarative nature. 1) useState allows the state variable to be declared directly in the function component, 2) it remembers the state during re-rendering through the hook mechanism, 3) use useState to utilize React optimizations such as memorization to improve performance, 4) But it should be noted that it can only be called on the top level of the component or in custom hooks, avoiding use in loops, conditions or nested functions.

UseuseState()forlocalcomponentstatemanagement;consideralternativesforglobalstate,complexlogic,orperformanceissues.1)useState()isidealforsimple,localstate.2)UseglobalstatesolutionslikeReduxorContextforsharedstate.3)OptforReduxToolkitorMobXforcomplexst

ReusablecomponentsinReactenhancecodemaintainabilityandefficiencybyallowingdeveloperstousethesamecomponentacrossdifferentpartsofanapplicationorprojects.1)Theyreduceredundancyandsimplifyupdates.2)Theyensureconsistencyinuserexperience.3)Theyrequireoptim


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.

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SublimeText3 Linux new version
SublimeText3 Linux latest version

Notepad++7.3.1
Easy-to-use and free code editor

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
