With this page you created your_number cookies with the value Unknown number from 1_form.php
If everything works - go to
the next example
Open the browser console and confirm the cookie appeared there
your_number with the number you set.
You can also see this cookie in the superglobal variable contents
$_COOKIE printed below:
Look for the line [your_number] => $your_number
If it is not there - refresh the page
Open the console by pressing SHIFT + CTRL + I
In
Firefox
cookies can be viewed in Storage → Cookies