The null coalesce operator

<h1>The null coalesce operator</h1>

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 - #0<hr>N/A - #1<hr>N/A - #2<hr>N/A - #3<hr>N/A - #4<hr><pre>
// #0
echo $_GET['name'] . ' - #0';
<hr>
// #1
if (isset($_GET['name']) && !empty($_GET['name'])) {
	$name = $_GET['name'];
} else {
	$name = 'N/A';
}
echo $name . ' - #1';
<hr>
// #2
if (!empty($_GET['name'])) {
	$name = $_GET['name'];
} else {
	$name = 'N/A';
}
echo $name . ' - #2';
<hr>
// #3
$name = ((isset($_GET['name']) && !empty($_GET['name']))) ? $_GET['name'] : 'N/A';
echo $name . ' - #3';
<hr>
// #4
$name = (!empty($_GET['name'])) ? $_GET['name'] : 'N/A';
echo $name . ' - #4';
<hr>
	
	
// #php7
//      muss existieren
//      und not null sein
//      VVVVVVVVVVVVV sonst wird 2. Wert übernommen
$name = $_GET['name'] ?? 'N/A';
echo $name . ' - #php7';

</pre>
<h1>Uniform variable syntax</h1>
<pre>
/*** expression syntax ***/
$$foo['bar']['baz']

// PHP 5.x meaning
${$foo['bar']['baz']}
// PHP 7.x meaning
($$foo)['bar']['baz']

/*** expression syntax ***/
$foo->$bar['baz']

// PHP 5.x meaning
$foo->{$bar['baz']}
// PHP 7.x meaning
($foo->$bar)['baz']
	
</pre>