Null Coalescing operator¶

binaryoperatorifthenconditional

Definition¶

$value ?? $default_value;

Usage¶

short for isset($value) ? $value : $default_value;

Examples¶

$width = $parameters['width'] ?? $default_width;
// which is equivalent to ternary operator
$width = isset($params['width']) ? $params['width'] : $default_width;

// chaining is possible
$width = $params['width'] ?? $params['resize_to'] ?? $default_width;

// null coalescing assignment operator (since PHP 7.4)
$person['language'] ??= 'en';
// which is equivalent to
$person['language'] = $person['language'] ?? 'en';

References¶

• Wikipedia: Null coalescing operator
• Shorthand comparisons in PHP

Related articles¶

• Ternary Operator ifthen operator conditional