Online PHP editor | refs for mt071

<?php function tryit($operand) { echo str_pad($operand, 4, ' ', STR_PAD_RIGHT); try { eval("\$a = []; \$a $operand \$a;"); echo "ok\n"; } catch (\Throwable $e) { echo $e->getMessage(), "\n"; } } tryit('+'); tryit('-'); tryit('-'); tryit('*'); tryit('/'); tryit('.'); tryit('**'); tryit('<=>');