What hook do I need to save a setting? - php

Question

I've added a new field onto the discussion's section on the /wp-admin/options-discussion.php page that outputs along with this:
<?php do_settings_sections('discussion'); ?>
How can I hook the Save Changes button so that I can handle saving my new setting's fields?
I've tried updated_option like so:
add_action('updated_option', [__CLASS__, 'sanitize_settings'], 11, 3);
But I don't think this is what I need.

Answer 1

for saving data in wp_options you should set the name and value together
for example first we can add new options with add_option function and see this link
add_option( 'nameOfYourOption', 'value', '', 'yes' );
then you can easily access your data with the get_option function and see this link
$yourOption = get_option( 'nameOfYourOption' );
var_dump($yourOption)
and if you want to change the value you can do that with update_option function and see this link
update_option( 'nameOfYourOption', 'newValue' );
With these three functions, you can manage your option
but if you try just using the hook for update_option see this link
do_action( 'update_option', string $option, mixed $old_value, mixed $value )
Updated
When you try to click on a Save button to using those functions, you can handle that with a form or with WordPress ajax
<form method="post">
<button name="uniqName" type="submit">Save Changes</button>
</form>
in wordpress/php
<?PHP
if(isset($_POST['uniqName'])){
//do something
}
and if you try to send data with ajax, just see this link