Constructing an array with a key from an Input array

Question

I have an array that has a list of PID, Email and Client in a comma delimited array. I was wondering if there's a way to parse the input array and generate a new array that has "Email" as the key and all unique PIDs for that email. Since the input array can have thousands of elements, I was wondering about the fastest approach.

Ex: Input Array (PID, Email, Client)
--------------------------------------
Array ( 
[0] => 10, [email protected],Gmail 
[1] => 11, [email protected],Gmail
[2] => 12, [email protected],Gmail 
[3] => 13, [email protected],Gmail
[4] => 14, [email protected],Gmail 
[5] => 15, [email protected],Gmail
)


Ex: Output Array (with Email as the key):
---------------------------------------------
Array (
[[email protected]] => (
                   [0] => 10
               [1] => 12
          ),
[[email protected]] => (
               [0] => 11
               [1] => 13
               [2] => 15
          ),
[[email protected]] => (
               [0] => 14
          )
)

Thanks

Where did the comma-delimited array come from? Are you calling fgets() on a CSV file? — user212218
– user212218, Commented Feb 27, 2012 at 20:28

Michael Berkowski · Accepted Answer · 2012-02-27 19:53:31Z

3

// $input holds your initial array:
// $ouput is output...
$output = array();
foreach ($input as $arr) {
  // Explode the comma-delimited lines into 3 vars
  list($pid, $email, $client) = explode(",", $arr);
  // Initialize a new array for the Email key if it doesn't exist
  if (!isset($output[$email])) $output[$email] = array();
  // Append the PID to the Email key
  $output[$email][] = $pid;
}

answered Feb 27, 2012 at 19:53

Michael Berkowski

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Comments

Travesty3 · Accepted Answer · 2012-02-27 19:54:52Z

1

Only way I can think of is this:

$outputArray = array();
foreach ($inputArray as $value)
{
    list($pid, $email) = explode(",", trim($value));
    $outputArray[$email][] = $pid;
}

answered Feb 27, 2012 at 19:54

Travesty3

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Comments

scibuff · Accepted Answer · 2012-02-27 19:58:48Z

0

$emails = array();

foreach( $array as $item ){
    $data = explode( ",", $item );
    $id = trim( $data[0] );
    $email = trim( $data[1] );
    if ( !isset( $emails[ $email ] ){ $emails[ $email ] = array(); }
    array_push( $emails[ $email ], $id );
}

edited Feb 27, 2012 at 19:58

answered Feb 27, 2012 at 19:54

scibuff

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