PHP best way of unsetting a variable

Question

$num = 1;    
$var = ''

if ($num == 1) {
  $var = 'ONE';
}

if (isset($var)) {
  echo $var;
}

// Result: ONE

In the above example, which is best practice when checking against isset() ?

$var = '';

or

$var = null;

Answer 1

It kind of depends more broadly on what you're trying to do.
I'm not convinced unsetting a variable is your best bet here.

However, PHP does have an unset function:

unset($var);

To be clear, I agree that checking for emptiness is probably a better idea

Answer 2

By setting $var = ''; near the top, isset will return true every time. What you want, is to check if the $var is empty .

Change:

if (isset($var)) {
  echo $var;
}

to

if (!empty($var)) {
  echo $var;
}

Otherwise, simply remove the original $var = ''; near the top and you can continue to use isset .