top in html5 means "top" and "distance from top". The top attribute is used to specify the top edge of the element. It can also be used to set the offset between the upper outer boundary of the positioned element and the upper boundary of its containing block. Shift, the syntax is "
" or "Object.style.top=value". <element style="top:值">
The operating environment of this tutorial: Windows 10 system, HTML5 version, Dell G3 computer.
#What does top mean in html5
The top attribute specifies the top edge of the element. This property defines the offset between the top margin boundary of a positioned element and the top boundary of its containing block.
Note: If the value of the "position" attribute is "static", then setting the "top" attribute will have no effect.
For static elements, it is auto; for length values, it is the corresponding absolute length; for percentage values, it is the specified value; otherwise, it is auto.
For relative definition elements, if top and bottom are both auto, their calculated values are both 0; if one of them is auto, the opposite of the other value is taken; if neither is auto, bottom will be the inverse of top's value.
The syntax is:
<element style="top:值">
The top attribute sets the offset between the top margin boundary of a positioned element and the top boundary of its containing block.
The syntax is:
Object.style.top=auto|%|length
The example is as follows:
<html>
<head>
<style type="text/css">
input
{
position:absolute;
}
</style>
<script type="text/javascript">
function setTopEdge()
{
document.getElementById("b1").style.top="100px";
}
</script>
</head>
<body>
<input type="button" id="b1" onclick="setTopEdge()"
value="Set top edge to 100 px" />
</body>
</html>Output result:
Recommended tutorial: "html video tutorial"
The above is the detailed content of What does top mean in html5. For more information, please follow other related articles on the PHP Chinese website!
The Benefits of React's Strong Community and EcosystemApr 29, 2025 am 12:46 AMReact'sstrongcommunityandecosystemoffernumerousbenefits:1)ImmediateaccesstosolutionsthroughplatformslikeStackOverflowandGitHub;2)Awealthoflibrariesandtools,suchasUIcomponentlibrarieslikeChakraUI,thatenhancedevelopmentefficiency;3)Diversestatemanageme
React's Component-Based Architecture: A Key to Scalable UI DevelopmentApr 29, 2025 am 12:33 AMReact's componentized architecture makes scalable UI development efficient through modularity, reusability and maintainability. 1) Modularity allows the UI to be broken down into components that can be independently developed and tested; 2) Component reusability saves time and maintains consistency in different projects; 3) Maintainability makes problem positioning and updating easier, but components need to be avoided overcomplexity and deep nesting.
The Size of React's Ecosystem: Navigating a Complex LandscapeApr 28, 2025 am 12:21 AMTonavigateReact'scomplexecosystemeffectively,understandthetoolsandlibraries,recognizetheirstrengthsandweaknesses,andintegratethemtoenhancedevelopment.StartwithcoreReactconceptsanduseState,thengraduallyintroducemorecomplexsolutionslikeReduxorMobXasnee
How React Uses Keys to Identify List Items EfficientlyApr 28, 2025 am 12:20 AMReactuseskeystoefficientlyidentifylistitemsbyprovidingastableidentitytoeachelement.1)KeysallowReacttotrackchangesinlistswithoutre-renderingtheentirelist.2)Chooseuniqueandstablekeys,avoidingarrayindices.3)Correctkeyusagesignificantlyimprovesperformanc
Debugging Key-Related Issues in React: Identifying and Resolving ProblemsApr 28, 2025 am 12:17 AMKeysinReactarecrucialforoptimizingtherenderingprocessandmanagingdynamiclistseffectively.Tospotandfixkey-relatedissues:1)Adduniquekeystolistitemstoavoidwarningsandperformanceissues,2)Useuniqueidentifiersfromdatainsteadofindicesforstablekeys,3)Ensureke
React's One-Way Data Binding: Ensuring Predictable Data FlowApr 28, 2025 am 12:05 AMReact's one-way data binding ensures that data flows from the parent component to the child component. 1) The data flows to a single, and the changes in the state of the parent component can be passed to the child component, but the child component cannot directly affect the state of the parent component. 2) This method improves the predictability of data flows and simplifies debugging and testing. 3) By using controlled components and context, user interaction and inter-component communication can be handled while maintaining a one-way data stream.
Best Practices for Choosing and Managing Keys in React ComponentsApr 28, 2025 am 12:01 AMKeysinReactarecrucialforefficientDOMupdatesandreconciliation.1)Choosestable,unique,andmeaningfulkeys,likeitemIDs.2)Fornestedlists,useuniquekeysateachlevel.3)Avoidusingarrayindicesorgeneratingkeysdynamicallytopreventperformanceissues.
Optimizing Performance with useState() in React ApplicationsApr 27, 2025 am 12:22 AMuseState()iscrucialforoptimizingReactappperformanceduetoitsimpactonre-rendersandupdates.Tooptimize:1)UseuseCallbacktomemoizefunctionsandpreventunnecessaryre-renders.2)EmployuseMemoforcachingexpensivecomputations.3)Breakstateintosmallervariablesformor
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.
EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function
SublimeText3 Chinese version
Chinese version, very easy to use
ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment
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.
