Question

I am not getting the concept of two dimensional arrays in PHP. I am trying to implement a cart system in which an array Session variable store productid and the quantity of it.
For every new entry if it exists its quantity should be increased or if it does’nt then a new id should be added.
Here is my initial code.

function cart_increment_ajax($data, $qtt) {
    $_SESSION['count']+=$qtt;
    set_cart( $data );
    echo $_SESSION['count'];
}

function initialise_cart( ) {
        $_SESSION['cart'] =array( );
        $_SESSION['totalprice'] = 0;
}

function set_cart( $pid )  {
                    if(!isset($_SESSION['cart'])) {
        initialise_cart( );
                     }
        //else if( int $_SESSION['cart'] pid exists increment count ))
                    else
                    //     ($_SESSION['cart'] add new pid.

}

I am not getting how to implement the commented lines through Multidimensional associative array ?

Answer 1

A small quick n dirty example of a multi-array in a session keeping a cart

<?php

function add_to_cart($product_id,$count)
{
    // no need for global $_SESSION is superglobal
    // init session variable cart
    if (!isset($_SESSION['cart']))
        $_SESSION['cart'] = array();
    // check if product exists
    if (!isset($_SESSION['cart'][$product_id]))
        $_SESSION['cart'][$product_id]=$count;
    else
        $_SESSION['cart'][$product_id]+=$count;
}

// add some foos and a bar
add_to_cart('foo',2);
add_to_cart('foo',1);
add_to_cart('bar',1);

print_r($_SESSION['cart']);
?>

This will produce

Array
(
    [foo] => 3
    [bar] => 1
)

HTH