Remove NULL, FALSE, and '' - but not 0 - from a PHP array

Question

I want to remove NULL, FALSE and \'\' values .

I used array_filter but it removes the 0\' s also.

Answer 1

array_filter doesn't work because, by default, it removes anything that is equivalent to FALSE, and PHP considers 0 to be equivalent to false. The PHP manual has this to say on the subject:

When converting to boolean, the following values are considered FALSE:

• the boolean FALSE itself
• the integer 0 (zero)
• the float 0.0 (zero)
• the empty string, and the string "0"
• an array with zero elements
• an object with zero member variables (PHP 4 only)
• the special type NULL (including unset variables)
• SimpleXML objects created from empty tags

Every other value is considered TRUE (including any resource).

You can pass a second parameter to array_filter with a callback to a function you write yourself, which tells array_filter whether or not to remove the item.

Assuming you want to remove all FALSE-equivalent values except zeroes, this is an easy function to write:

function RemoveFalseButNotZero($value) {
  return ($value || is_numeric($value));
}

Then you just overwrite the original array with the filtered array:

$array = array_filter($array, "RemoveFalseButNotZero");