Example of php variable type judgment

$s = "this is a string";
$i = 9;
$arr = array(2,4,6);
is_string($s); //return TRUE , indicating that $s is a string variable
is_string($i); //Returns FALSE, indicating that $i is not a string variable
is_array($arr); //Returns TRUE, indicating that $arr is an array
is_array( $s); //Return FALSE, indicating that $s is not an array
$str = "this is a string";
$int = 9;
$bool = FALSE;
echo "The type of $str is:".gettype ($str);
echo "";
echo "";
echo "The type of $int is: ".gettype($int);
echo "";
echo "";
echo "The type of $bool is: ".gettype($bool);
?>