- var_dump: documentation ( source)
- is_nan: documentation ( source)
- print_r: documentation ( source)
<?php
$things = [NAN, is_nan(NAN), is_float(NAN), is_int(NAN), var_dump(NAN)];
$len = count($things);
for ($i = 0; $i < $len; $i++) {
print_r($things[$i] + "\n");
}