Wednesday 17 April 2019

C#'s null coalescing operator (??) in PHP



Is there a ternary operator or the like in PHP that acts like ?? of C#?



?? in C# is clean and shorter, but in PHP you have to do something like:



// This is absolutely okay except that $_REQUEST['test'] is kind of redundant.

echo isset($_REQUEST['test'])? $_REQUEST['test'] : 'hi';

// This is perfect! Shorter and cleaner, but only in this situation.
echo null? : 'replacement if empty';

// This line gives error when $_REQUEST['test'] is NOT set.
echo $_REQUEST['test']?: 'hi';

Answer



PHP 7 adds the null coalesce operator:




// Fetches the value of $_GET['user'] and returns 'nobody'
// if it does not exist.
$username = $_GET['user'] ?? 'nobody';
// This is equivalent to:
$username = isset($_GET['user']) ? $_GET['user'] : 'nobody';


You could also look at short way of writing php's ternary operator ?: (php >=5.3 only)




// Example usage for: Short Ternary Operator
$action = $_POST['action'] ?: 'default';

// The above is identical to
$action = $_POST['action'] ? $_POST['action'] : 'default';


And your comparison to C# is not fair. "in PHP you have to do something like" - In C# you will also have a runtime error if you try to access a non-existent array/dictionary item.


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