how to loop through this array and get the sum?

Question

I got stuck, my objective was to get the ProductID, hidden inside the $_SESSION['cart'] and then use those ID in an sql query to compute the sum

here's my code

public function getProductID(){
    $keys = array_keys($_SESSION['cart']);
    return $keys;
}


public function getShippingFee(){
    $ids = $this->getProductID();
    foreach($ids as $id){
    $query = mysql_query("SELECT * FROM deliverycharges WHERE ProductID = $id");
    $row = mysql_fetch_assoct($query);
    $sum = $row['Cost'] + $row['Tax'];
    return $sum;   
  }
}

the second function that I pasted is wrong, I have done several type of looping and yet, I can't get the real sum..shame on me

Before you can create a sum, you need to know of what to create the sum. That's entirely not clear from your question. In general you create a sum by using +, so your code looks good. — hakre
– hakre, Commented Jan 23, 2012 at 14:43
It isn't advisable to perform a query inside a loop. You'd better build a single query to retrieve all the results and then parse them with a loop. Apart from that, you'd better escape that $id var before passing it to MySQL, just to be sure. — entropid
– entropid, Commented Jan 23, 2012 at 14:44
You are overwriting the $sum variable in the for-each loop. Try this instead: $sum += $row['Cost'] + $row['Tax']; — Frankline
– Frankline, Commented Jan 23, 2012 at 14:47

bardiir · Accepted Answer · 2012-01-23 14:43:55Z

6

After you return, the function is exited, so you need to sum everything up at first and then return that after everything is summed up:

public function getShippingFee(){
    $ids = $this->getProductID();
    foreach($ids as $id){
      $query = mysql_query("SELECT * FROM deliverycharges WHERE ProductID = $id");
      $row = mysql_fetch_assoc($query);
      $sum += $row['Cost'] + $row['Tax'];
    }
    return $sum; 
}

answered Jan 23, 2012 at 14:43

bardiir

14.8k9 gold badges45 silver badges66 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Nick Garvey · Accepted Answer · 2012-01-23 14:44:40Z

0

You are overwriting the value of sum each loop. Use +=

public function getShippingFee() {
    $ids = $this->getProductID();
    $sum = 0;
    foreach($ids as $id) {
        $query = mysql_query("SELECT * FROM deliverycharges WHERE ProductID = $id");
        $row = mysql_fetch_assoct($query);
        $sum += $row['Cost'] + $row['Tax'];
    }
    return $sum;   
}

answered Jan 23, 2012 at 14:44

Nick Garvey

3,0001 gold badge27 silver badges33 bronze badges

Collectives™ on Stack Overflow

how to loop through this array and get the sum?

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related