php - It is possible to merge more than two of 2d array that have different element number? [duplicate]

Question

This question already has answers here:

php - how to merge 2d array that have different no of element for each array (4 answers)

Closed 8 years ago.

I have 3 set of 2d array that have different element number?One is the array that need to be as key(date and time) to compare with other two array.The other two array must in sequence.For row that empty, i want set as -9999.

First array :

Array (   
       [0] => Array
          (
            [0] => 01/7/2013
            [1] => 12.00 a.m

          )

       [1] => Array
          (
            [0] => 01/7/2013
            [1] => 12.01 a.m

          )

       [2] => Array
          (
            [0] => 01/7/2013
            [1] => 12.02 a.m

          )

      )

For second array:

Array(   

   [0] => Array
       (
          [0] => 01/7/2013
          [1] => 12.01 a.m
          [2] => 9.02
       )
 )

For Third array:

 Array(   
    [0] => Array
        (
            [0] => 01/7/2013
            [1] => 12.00 a.m
            [2] => 1.23
            [3] => 6.1
        )

    [1] => Array
        (
            [0] => 01/7/2013
            [1] => 12.02 a.m
            [2] => 1.75
            [3] => 1.75
        )

  )

and i need the output as:

Array(   
    [0] => Array
        (
            [0] => 01/7/2013
            [1] => 12.00 a.m
            [2] => -9999
            [3] => 1.23
            [4] => 6.1
        )

    [1] => Array
        (
            [0] => 01/7/2013
            [1] => 12.01 a.m
            [2] => 9.02
            [3] => -9999
            [4] => -9999
        )
    [2] => Array
        (
            [0] => 01/7/2013
            [1] => 12.02 a.m
            [2] => -9999
            [3] => 1.75
            [4] => 1.75
        )
 )

Answer 1

$arr = array_merge($arr1, $arr2, $arr3);
$out = array();
$cnt = 0;
foreach ($arr as $key => $value){
    $date = explode('/', $value[0]);//Change date format
    $dex = strtotime($date[1].'/'.$date[0].'/'.$date[2].' '.$value[1]);
    $head = (array_key_exists($dex, $out)) ? $out[$dex] : array_slice($value, 0, 2);
    $out[$dex] = array_merge($head, array_slice($value, 2));
    $cnt = ($cnt > count($out[$dex])) ? $cnt : count($out[$dex]);
}
$out = array_map(function ($e) use ($cnt){
    return array_pad($e, $cnt, '-9999');
}, array_values($out));
print_r($out);

That works for PHP 5.3 and later. For older versions of PHP, you can replace the array_map function with the following:

foreach ($out as $key => $value){
    $res[] = array_pad($value, $cnt, -9999);
}
print_r($res);

NEW VERSION (for PHP 5.3 or later):

$template = array();
array_walk($arr1, function (&$e, $k) use (&$template){
    $date = explode('/', $e[0]);
    $dex = strtotime($date[1].'/'.$date[0].'/'.$date[2].' '.$e[1]);
    $template[$dex][0] = '-9999';
});
$arr1 = array_combine(array_keys($template), $arr1);
$out = array();
$data = array($arr2, $arr3);
foreach ($data as $key => $value){
    foreach ($value as $key2 => $value2){
        $date = explode('/', $value2[0]);//Change date format
        $dex = strtotime($date[1].'/'.$date[0].'/'.$date[2].' '.$value2[1]);
        $out[$key][$dex] = array_slice($value2, 2);
    }
    $out[$key] += array_diff_key($template, $out[$key]);
    foreach ($out[$key] as $key2 => $value2){
        $arr1[$key2] = array_merge($arr1[$key2], $value2);
    }
}
print_r(array_values($arr1));