


How do I use the selected attribute to specify the default selected option?
Jun 23, 2025 am 12:49 AMTo set the ; if multiple options set this property, the browser will only select the first one; common precautions include avoiding spelling errors (such as written as selected), avoiding duplicate settings, and using JavaScript for dynamic control; in the back-end combined scenario, selected attributes can be dynamically inserted through the template engine or framework, for example, in PHP, conditions can be used to determine the output selected; finally, it is recommended to check whether the default item is correct to avoid errors caused by copy and paste.
In HTML forms, if you want a <option></option>
to be selected by default when the page is loaded, the most direct way is to add selected
attribute to the option. This property is of Boolean type. As long as it exists, it means that the option is selected by default and no additional assignment is required.
How to use selected
attribute correctly
In terms of writing, you just need to add selected
to the <option></option>
tag you want to select by default. For example:
<select name="fruit"> <option value="apple">Apple</option> <option value="banana" selected>Banana</option> <option value="orange">Orange</option> </select>
In this example, "Banana" is displayed by default when the page loads.
It should be noted that if multiple options are added with selected
, the browser will usually only select the first one that appears.
Frequently Asked Questions and Precautions
- Error spelling : Make sure the property name is
selected
, notselecteded
orselect
. - Don't repeat the settings : a drop-down menu usually only sets one default option to avoid user confusion.
- Dynamic control? It is more appropriate to use JavaScript : If you need to change the default selection according to user's operations or other conditions, you should use JS to operate
selectedIndex
orvalue
attribute.
Scenarios used in combination with the backend
Sometimes we read data from the database to generate form content, and at this time we can dynamically insert selected
attributes based on the data. For example, in PHP, it might be written like this:
<option value="banana" <?php if ($default == 'banana') echo 'selected'; ?>>Banana</option>
Similar logic is also applicable to other template engines or front-end frameworks (such as React and Vue), but the processing method will be more modern.
Basically that's it. Using the selected
property is simple, but it is also easy to make mistakes due to copying and pasting or forgetting to update the status. So remember to check whether the default item is correct after writing.
The above is the detailed content of How do I use the selected attribute to specify the default selected option?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

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

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

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

ARIA's role attribute is used to define the role of web elements and improve accessibility. 1. Role attribute helps assistive technology to understand the functions of elements, such as buttons, navigation, etc. 2. Use role attributes to assign specific roles to non-semantic HTML elements. 3. The role attribute should be consistent with the element behavior and be verified by the accessibility tool test.

How to create a website layout? 1. Use HTML tags to define the content structure, such as, ,. 2. Control styles and positions through CSS, using box model, float or Flexbox layout. 3. Optimize performance, reduce HTTP requests, use cache and optimize images, and ensure responsive design.

Improve the readability and maintainability of HTML code can be achieved through the following steps: 1. Use semantic tags, such as, etc. to make the code structure clear and improve SEO effect; 2. Keep the code formatted and use consistent indentation and spaces; 3. Add appropriate comments to explain the code intention; 4. Avoid excessive nesting and simplify the structure; 5. Use external style sheets and scripts to keep the HTML concise.

The key to keep up with HTML standards and best practices is to do it intentionally rather than follow it blindly. First, follow the summary or update logs of official sources such as WHATWG and W3C, understand new tags (such as) and attributes, and use them as references to solve difficult problems; second, subscribe to trusted web development newsletters and blogs, spend 10-15 minutes a week to browse updates, focus on actual use cases rather than just collecting articles; second, use developer tools and linters such as HTMLHint to optimize the code structure through instant feedback; finally, interact with the developer community, share experiences and learn other people's practical skills, so as to continuously improve HTML skills.

The reason for using tags is to improve the semantic structure and accessibility of web pages, make it easier for screen readers and search engines to understand page content, and allow users to quickly jump to core content. Here are the key points: 1. Each page should contain only one element; 2. It should not include content that is repeated across pages (such as sidebars or footers); 3. It can be used in conjunction with ARIA properties to enhance accessibility. Usually located after and before, it is used to wrap unique page content, such as articles, forms or product details, and should be avoided in, or in; to improve accessibility, aria-labeledby or aria-label can be used to clearly identify parts.

To create a basic HTML document, you first need to understand its basic structure and write code in a standard format. 1. Use the declaration document type at the beginning; 2. Use the tag to wrap the entire content; 3. Include and two main parts in it, which are used to store metadata such as titles, style sheet links, etc., and include user-visible content such as titles, paragraphs, pictures and links; 4. Save the file in .html format and open the viewing effect in the browser; 5. Then you can gradually add more elements to enrich the page content. Follow these steps to quickly build a basic web page.

HTMLtagsareessentialforstructuringwebpages.Theydefinecontentandlayoutusinganglebrackets,ofteninpairslikeand,withsomebeingself-closinglike.HTMLtagsarecrucialforcreatingstructured,accessible,andSEO-friendlywebpages.

To create an HTML checkbox, use the type attribute to set the element of the checkbox. 1. The basic structure includes id, name and label tags to ensure that clicking text can switch options; 2. Multiple related check boxes should use the same name but different values, and wrap them with fieldset to improve accessibility; 3. Hide native controls when customizing styles and use CSS to design alternative elements while maintaining the complete functions; 4. Ensure availability, pair labels, support keyboard navigation, and avoid relying on only visual prompts. The above steps can help developers correctly implement checkbox components that have both functional and aesthetics.
