Better than empty()

Value	Bool	empty()	!isset()	is_blank()
undefined	undefined	True	True	True
`NULL`	False	True	True	True
`bool(false)`	False	True	False	True
`bool(true)`	True	False	False	False
`int(0)`	False	True	False	False
`float(0)`	False	True	False	False
`int(1)`	True	False	False	False
`float(1)`	True	False	False	False
`string(1) "0"`	False	True	False	False
`string(3) "0.0"`	True	False	False	False
`string(1) "1"`	True	False	False	False
`string(3) "1.0"`	True	False	False	False
`string(0) ""`	False	True	False	True
`string(1) " "`	True	False	False	True
`string(4) "test"`	True	False	False	False
`array(0) { }`	False	True	False	True
`array(1) { [0]=> int(1) }`	True	False	False	False
`object(stdClass)#1 (0) { }`	True	False	False	False

Source code of empty.lib.php

<?php
/**
 * Checks if a scalar value is FALSE, without content or only full 
 * whitespaces. 
 * For non-scalar values will evaluate if value is empty().
 *
 * @param  mixed  $v  to test
 * @return  bool  if $v is blank
 */
function is_blank (&$v)
{
    return !isset($v) || (is_scalar($v) ? (trim($v) === '') : empty($v));
}
?>