- constant: documentation ( source)
- define: documentation ( source)
<?php
define('CONSTANT', 1);
define('_CONSTANT', 0);
define('EMPTY', '');
$a = '1';
if (!empty($a)) {
if (!(boolean) _CONSTANT) {
echo 1;
}
} else if (constant('CONSTANT') == 1) {
echo 2;
}