php shorthand if

I’ve known about the shorthand if for years:

<?php echo ($username) ? $username : ''; ?>

Today If saw this which is called Ternary and has been available since 5.3 which is older than my days of coding….

<?php echo ($username) ?: ''; ?>

Update PHP7.4
When assigning value especially in an array or object you can now do the following.

<?php

$person = [ 'date_of_birth' => '1970-01-01' ];

$person['name'] = $person['name'] ?? 'John Doe'; //php7.3
$person['name'] ??= 'John Doe';                  //php7.4

var_dump( $person );