php编辑for循环中的数组值

Question

I have an array of arrays, and I want to loop them while assigning a new key-value for each. But the original array fails to response. Here is my try:

<?php
$cards = array(
    array(
        "test" => 1  
    ),array(
        "test" => 2      
    )
);

foreach($cards as $card){
    $card["success"] = 1;
}

print_r($cards);

OUTPUT:

Array
(
    [0] => Array
        (
            [test] => 1
        )

    [1] => Array
        (
            [test] => 2
        )

)

How can I modify the method hence the 'success' value can be inserted into each of them?

Answer 1

Passing array elements by reference (notice the & sign):

foreach($cards as &$card){
    $card["success"] = 1;
}