davidstrauss/default-null.php

## default-null.php
<?php

function hello(array $x = null) {  // Removing the "= null" will cause the call below to have a fatal error.
  echo "hello\n";
}

hello(null);
	<?php

	function hello(array $x = null) { // Removing the "= null" will cause the call below to have a fatal error.
	echo "hello\n";
	}

	hello(null);