find the total values get in a variable in php

i am doing a shopping cart.i had a variable $total.when i add 1st product of price 200 i get $total=200 , when i add 2nd product of price 100 i get $total=200100 when i add 3rd product of price 400 i get $total=200100400 . i want to get $total=700. how to fix this problem?

 session_start();
           $ar20=Db::getInstance()->ExecuteS('SELECT * FROM '._DB_PREFIX_.'price WHERE id="'.$_SESSION['y'].'"  AND prodid="'.$row['id_product'].'" ORDER BY size DESC');

            for($i=0;$i < count($ar20);$i++)
            {
                $test=$test+$ar20[$i]['price'];
            }




 开发者_C百科            $row['price'] += $test ;
 $row['total'] = $row['price'] * intval($row['quantity']);

if 3 products then echo the $row['total'] will get this 100200300

Use + instead of . operator

Just get the value of price each time and add it in previous on like wise, the below logic may help u say $newprice is a variable where u get the price..

$total = 0;
$total +=$newprice;

Are you doing this?

$total = '100';
$total += '300';
$total += '300';
echo $total;

PHP is forgiving to a point, especially to the JavaScript fans: It allows you to use the + operator as concatenation if the operands are both strings. Make sure that you don't surround them in quotes, single or double, like so:

$total = 100;
$total += 300;
$total += 300;
echo $total;

Your code isn't clear because it has no context, but this should work:

$test = (integer) $test;

for($i=0; $i < count($ar20); $i++)
{
    $test = $test + (integer) $ar20[$i]['price'];
}

$row['price'] = (integer) $row['price'] + (integer) $test;

$row['total'] = $row['price'] * intval($row['quantity']);

session_start();

$records=Db::getInstance()->ExecuteS('SELECT * FROM '._DB_PREFIX_.'price WHERE id="'.$_SESSION['y'].'"  AND prodid="'.$row['id_product'].'" ORDER BY size DESC');

$row = array();
$test = '0';

if (count($records) < 1) {
    $row['price'] = '0';
    $row['total'] = '0';
} else {
    foreach($records as $record)
    {
        $test = bcadd($test, $record['price']);
    }

    $row['price'] = bcadd($row['price'], $test);
    $row['total'] = bcmul($row['price'], $row['quantity']);
}

PHP: bcadd