how to use set_select on a form to show the old value?

https://codeigniter.com/user_guide/helpe...m_dropdown
option must contain "selected=selected". Learn HTML syntax

I know it must contain selected, I am expecting the set_value to do that for me. 

You are pointing to another part of the documentation that is not the one I am referring to. In the one I am mentionning, here's what is said and the example:

Code:

set_select($field[, $value = ''[, $default = false]])

If you use a <select> menu, this function permits you to display the menu item that was selected.

The first parameter must contain the name of the select menu, the second parameter must contain the value of each item, and the third (optional) parameter lets you set an item as the default (use boolean true/false).

Example:

<select name="myselect">
    <option value="one" <?= set_select('myselect', 'one', true) ?>>One</option>
    <option value="two" <?= set_select('myselect', 'two') ?>>Two</option>
    <option value="three" <?= set_select('myselect', 'three') ?>>Three</option>
</select>

It's what I am doing, so what is missing?


// Edit 
I confirm after multiple attempts, the example is correct, and the set_select function should return selected (which is enough in HTML to make the option selected). But In my case, it looks like it returns nothing. So if any one has an idea what's happening?