Question

I have a strange problem.

If have function that does this return the value,

public function isVipCustomer($customer_id){
        $cus_vip_id=FALSE;
        $sql="SELECT customerid FROM customers WHERE is_vip='1' 
                AND customerid='".$customer_id."' LIMIT 0,1 ";  
        $result= $this->db->query($sql);

        while($row=mysqli_fetch_assoc($result)){
            $cus_vip_id=(int)$row['customerid'];    
        }

        if($cus_vip_id!=0)
            return TRUE;
        else
            return FALSE;

    }

when I call

$customer_id=13;
echo $collection->isVipCustomer($customer_id);

when its true it outputs 1 but when its false its empty, expecting a output of 0

why?

Answer 1

From the PHP documentation:

A boolean TRUE value is converted to the string “1”. Boolean FALSE is
converted to “” (the empty string). This allows conversion back and
forth between boolean and string values.

http://www.php.net/manual/en/language.types.string.php

To print the return value back with the type, try using var_dump($myVar) instead.