I'm writing a registration form with html/php. However, I also included a captcha, which will be verified by my php-scripts after the user has submitted the form.
In case the captcha was wrong, I don't want the user having to retype everything into the form again. How can I pre-fill the information that was already entered back into those fields?
Assuming that you are rendering on the post request only here is a sample code you can use
<form>
<input type="text" placeholder="name" value=<?php echo $_POST["name"];?>>
// Code for captcha
</form>
Do remember to sanitize the POST according to your use case or it would lead to XSS on your form.