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Table of Contents
How to use selected attribute correctly
Frequently Asked Questions and Precautions
Scenarios used in combination with the backend
Home Web Front-end HTML Tutorial How do I use the selected attribute to specify the default selected option?

How do I use the selected attribute to specify the default selected option?

Jun 23, 2025 am 12:49 AM
Default options

To 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 , not selecteded or select .
  • 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 or value 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 == &#39;banana&#39;) echo &#39;selected&#39;; ?>>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.

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