When validating that an integer falls in a range the check includes the minimum and maximum bounds:
$options = array(
'options' => array(
'min_range' => 5,
'max_range' => 10,
)
);
var_dump(filter_var('5', FILTER_VALIDATE_INT, $options));
var_dump(filter_var('10', FILTER_VALIDATE_INT, $options));
var_dump(filter_var('8', FILTER_VALIDATE_INT, $options));
var_dump(filter_var('4', FILTER_VALIDATE_INT, $options));
var_dump(filter_var('11', FILTER_VALIDATE_INT, $options));
var_dump(filter_var('-6', FILTER_VALIDATE_INT, $options));
Results:
int(5)
int(10)
int(8)
bool(false)
bool(false)
bool(false)