How to implement the online clock function of web pages in javascript

First, check whether the src attribute path is correct, and ensure that the relative or absolute path matches the HTML file location; 2. Verify whether the file name and extension are spelled correctly and case-sensitive; 3. Confirm that the image file actually exists in the specified directory; 4. Use appropriate alt attributes and ensure that the image format is .jpg, .png, .gif or .webp widely supported by the browser; 5. Troubleshoot browser cache issues, try to force refresh or directly access the image URL; 6. Check server permission settings to ensure that the file can be read and not blocked; 7. Verify that the img tag syntax is correct, including the correct quotes and attribute order, and finally troubleshoot 404 errors or syntax problems through the browser developer tool to ensure that the image is displayed normally.

Thetagisusedtodefinecontactinformationfortheauthororownerofadocumentorsection;1.Useitforemail,physicaladdress,phonenumber,orwebsiteURLwithinanarticleorbody;2.Placeitinsideforauthorcontactorinfordocument-widecontact;3.StyleitwithCSSasneeded,notingdefa

Thebdotagisusedtooverridethebrowser’sdefaulttextdirectionrenderingwhendealingwithmixedleft-to-rightandright-to-lefttext,ensuringcorrectvisualdisplaybyforcingaspecificdirectionusingthedirattributewithvalues"ltr"or"rtl",asdemonstrat

To set the default value for HTMLselect elements, the corresponding option element must be marked with the selected attribute; 1. Add the selected attribute to the option you want to select by default, such as UnitedStates; 2. Ensure that only one option in a single select has selected attribute, and if there are multiple ones, the first one will be the source code order; 3. The selected attribute can be placed anywhere in the list, not limited to the first option; 4. This method is suitable for single-select and multiple-select select; 5. If you need to set it dynamically, you can use JavaScript to operate the value attribute, such as document.querySelec

TheasyncattributeinHTMLisusedtoloadandexecuteexternalJavaScriptfilesasynchronously,allowingthebrowsertodownloadthescriptinparallelwithHTMLparsingandexecuteitimmediatelyuponcompletion,whichimprovespageloadperformancebypreventingrender-blocking;itisbes

Tocenteradivhorizontally,usemargin:0autowithadefinedwidth.2.Forhorizontalandverticalcentering,applydisplay:flexontheparentwithjustify-content:centerandalign-items:center.3.Alternatively,useCSSGridwithplace-items:centerforbothdirections.4.Asafallback,

Theelementisusedforsidecomments,fineprint,orlessimportantcontentwithsemanticmeaning,notjustvisualstyling;2.Itisappropriateforcopyrightnotices,legaldisclaimers,attributions,andlimitations;3.Itshouldnotbeusedsolelytoreducetextsize—CSSshouldhandlepresen

You can use CSS to change the bullet style of HTML lists, because HTML is only responsible for the structure and CSS controls the appearance; you can set built-in styles such as disc, circle, square, or none through the list-style-type attribute, use list-style-image to replace it with a custom image, or use background-image and padding to control the image position more accurately on the li element. You can also use pseudo-element::before combined with Unicode characters or web fonts (such as FontAwesome) to add custom symbols, thereby achieving flexible and diverse list style design.