It depend on how many values to check using in_array. If more than two, better way is loops through array and runs an in_array of it on the checking array. Returns true once something is found, else it returns false.
Examples:
<?php
$main_array = array(1,2,3,4,5);
$check_value = array(1,3,6,8);
foreach ($check_value as $value) {
if (in_array($value, $main_array)) {
true;
} else {
return false;
}
}
?> <?php
if(in_array('foo',$arg) && in_array('bar',$arg)){
//both of them are in $arg
}
if(in_array('foo',$arg) || in_array('bar',$arg)){
//at least one of them are in $arg
}
?> 
