Check if variable is set and then echo it without repeating?

Question

Is there a concise way to check if a variable is set, and then echo it without repeating the same variable name?

Instead of this:

Answer 1

Update:

PHP 7 introduces a new feature: Null coalescing operator

Here is the example from php.net.

For those not using PHP7 yet here is my original answer...

I use a small function to achieve this:

function ifset(&$var, $else = '') {
  return isset($var) && $var ? $var : $else;
}

Example:

$a = 'potato';

echo ifset($a);           // outputs 'potato'
echo ifset($a, 'carrot'); // outputs 'potato'
echo ifset($b);           // outputs nothing
echo ifset($b, 'carrot'); // outputs 'carrot'

---

Caveat: As Inigo pointed out in a comment below one undesirable side effect of using this function is that it can modify the object / array that you are inspecting. For example:

$fruits = new stdClass;
$fruits->lemon = 'sour';
echo ifset($fruits->peach);
var_dump($fruits);

Will output:

(object) array(
  'lemon' => 'sour',
  'peach' => NULL,
)