从多维数组php获取值

Question

I would like to make multidimensional array but after looking on it for hours I am quite lost. I am sending ID and quantity from modal via AJAX, and I want to store it like this $_SESSION['cart'] =>array(here should be IDs => and each ID is pointing to its quantity)

if(!isset($_SESSION['cart'])){
    $_SESSION['cart'] = array(array());
}

if(isset($_REQUEST['id'])){
    $_SESSION['cart'][] = $_REQUEST['id'];
    $_SESSION['cart'][][] = $_REQUEST['quantity'];
}

I am trying to access it like that:

foreach($_SESSION['cart'] as $value){
    //var_dump($value);
    //echo "<br>";
    foreach($value as $item){
        var_dump($item);
        echo "<br>";
    }
}

But for second foreach I get warning that its argument is invalid, which I can bypass with converting the $value to array. Is this the right way to do it ? or is there any better ? Thanks

Answer 1

Type these in your address bar:

/path/to/your/file.php?id=10&quantity=20
/path/to/your/file.php?id=11&quantity=30
/path/to/your/file.php?id=12&quantity=15
/path/to/your/file.php?id=10&quantity=80

file.php

session_start();

if(!isset($_SESSION['cart'])){
$_SESSION['cart']=array();
}


if(isset($_REQUEST['id'])){
    foreach ($_SESSION['cart'] as $index => $item) {
        if (  array_key_exists($_REQUEST['id'],$item)   ) {
            $_SESSION['cart'][$index][$_REQUEST['id']] = $_REQUEST['quantity'];
            $flag=1;
            break;
        }       
    }
    if ($flag==0) {
        $_SESSION['cart'][] = array($_REQUEST['id'] => $_REQUEST['quantity']);
    }   
}


foreach ($_SESSION['cart'] as $index => $item) {
    foreach ($item as $id => $quantity) {
        echo 'id is :'.$id.', quantity is:'.$quantity.'<br>';
    }
}

Result:

id is :10, quantity is:80(20 previous)
id is :11, quantity is:30
id is :12, quantity is:15