如何获得$ _SESSION数组的一部分？

Question

How do I get a part of a $_session array?

<?php
session_start();

foreach($_SESSION['cart'] as $product_id => $quantity) {
    echo $product_id . "=>" . $quantity . "<br>";

}
?>

This outputs

1 => 6
4 => 5
2 => 5 

But what I ultimately want is the value of only one of them. Lets say I only want the second( 4 => 5 ).

So I tried this :echo $_SESSION['cart'][1]; And ofcourse it showed me nothing.

So my question is how to get it. Sorry if this is a stupid/unclear question.

Answer 1

I am not able to replicate your issue.

Check this test.php:

<?php

// Start PHP Session
session_start();

// Dummy Data
$_SESSION['cart'] = array(
    1 => 6,
    4 => 5,
    2 => 5
);

// Helper Function
function getSessionCartData($key) {
    if (isset($_SESSION['cart'][$key])) {
        return $_SESSION['cart'][$key];
    }
    return false;
}

// Usage
var_dump(getSessionCartData(4));

Output:

int 5