How to implement is_empty() in PHP?

Question

The empty() native in PHP will fail if the string is "0" or something like that.

So how to implement the exact is_empty() function in PHP?

Answer 1

Quite simple, check for the error case described above. If you run into it, return the result you want. If not, call empty() and return that result.

Answer 2

try this:

function is_empty(&$val) {
  return empty($val) && $val !== "0";
}

&$val is needed, so you don’t get a warning on undefined variables.

if you only want to check if a variable is set (regardless of its value) you should use PHP’s isset

Answer 3

You may want to use isset if you are trying to check if that variable is defined.

Answer 4

Check out the type comparison table in the PHP manual for the exact behaviour of empty(), isset(), is_null() etc. You'll probably find what you're looking for there.