Output a multidimensional array in groups

Question

I have an multidimensional array of data which represents the list of users that are connected to our servers. Each array contains information about a connection. The same user could be connected to any number of ports on different servers.

Array(  [0] => Array(
            [0] => serverA
            [1] => port1,
            [2] => user1,
            [3] => ip1
        ),
        [1] => Array(
            [0] => serverB
            [1] => port2,
            [2] => user2,
            [3] => ip2
            ),
        [2] => Array(
            [0] => serverC
            [1] => port1,
            [2] => user3,
            [3] => ip3
            ),  
        [3] => Array(
            [0] => serverA
            [1] => port1,
            [2] => user4,
            [3] => ip4
            ),  
        [4] => Array(
            [0] => serverB
            [1] => port4,
            [2] => user5,
            [3] => ip5
            ),  
        [5] => Array(
            [0] => serverC
            [1] => port1,
            [2] => user6,
            [3] => ip6
            ),
        [6] => Array(
            [0] => serverA
            [1] => port2,
            [2] => user7,
            [3] => ip7
            ),              
)

I need to group by first the servers and then the ports and print out a list showing the connected users for each server and port as below:

ServerA
    port1
        user1,ip1
        user4,ip4
    port2
        user7,ip2
ServerB
    port2
        user2,ip2
    port4
        user5,ip5
ServerC
    port1
        user3,ip3
        user6,ip6

I'm confused as to how to approach this. Should I be using a multidimensional array sort function (e.g. array_multisort) or should I be building a new array? An examples would be greatly appreciated.

Answer 1

You can create a new array where you summarize the data and then print it in the required format:

$newArr = array();

foreach($arr as $k => $v) {
        if(!isset($newArr[$v[0]][$v[1]])) {
                $newArr[$v[0]][$v[1]] = array();
        }
        $newArr[$v[0]][$v[1]][] = array($v[2],$v[3]);
}

foreach($newArr as $k => $v) {
        echo $k,"\n";
        foreach($v as $k1 => $v1) {
                echo "\t$k1\n";
                foreach($v1 as $k2 => $v2) {
                        echo "\t\t", $v2[0],",",$v2[1],"\n";
                }
        }

        echo "\n";
}

See it

Answer 2

First of all this is an impossible array. Because in an array the array key must be unique, so you wont be able to have two values for serverA

you have

[serverA] => Array (
        [0] => port1,
        [1] => user1,
        [2] => ip1
        ),
[serverA] => Array (
        [0] => port1,
        [1] => user4,
        [2] => ip4
        ),
[serverA] => Array (
        [0] => port2,
        [1] => user7,
        [2] => ip7
        ),

Please check the array and re-phrase the question.