PHP Knowledge Base

The Ternary Operator

Example of Standard if/then/else Conditional Statement

if( $valid ) {
    $x = 'yes';
} else {
    $x = 'no';
}

Above Example Written Using the Ternary Operator

$x = $valid ? 'yes' : 'no';

Verifying the (non-)existence of the value and using the default 2

NOTE: ?? is the equivalent of isset().
Example #1
echo $mainCategory ?? 'The category does not exist';
Example #2
echo "<td>$sell_date</td>" ?? "<td>&nbsp;</td>";
Example #3
Replace
if(isset($_SESSION['username'])) { echo $_SESSION['username']; }
With
echo $_SESSION['username'] ?? '';

Ternary Shorthand (PHP 5.3+)

Example of Standard if/then Conditional Statement

if( !$start ) {
    $start = 1;
}

Above Example Written Using Ternary Shorthand

$start = $start ?: 1;
NULL