$s, $v and $x functions to work with form items in Javascript in Oracle Apex

Page items and Javascript: More than $s and $v ...

Today, most APEX applications do contain more or less Javascript code. Javascript is particularly useful to make forms more interactive and
therefore more user-friendly. Most developers know and already have used the $s, $v and $x functions to work with form items in Javascript.
$s sets an item value, $v retrieves it and $x determines whether an item with the given name exists on the current page.
These functions are available in Application Express for a long time. And the names are so nicely short and quickly typed. But actually this is
shortcut syntax for the functions within the "apex.item" Javascript namespace. And within apex.item, there are more functions than you might
think.