$v = 1;
echo gettype($v) . "\n";
$v = 3.14;
echo gettype($v) . "\n";
$v = "php";
echo gettype($v) . "\n";
$v = null;
echo gettype($v) . "\n";
$v = array();
echo gettype($v) . "\n";
$v = new stdClass;
echo gettype($v) . "\n";
/*
run:
integer
double
string
NULL
array
object
*/