Merge 2 arrays by appending values

Question

I have 2 arrays

$a = array('v1'=>1,'v2'=>2,'v3'=>3,'v4'=>4);

$b = array('v1'=>1,'v2'=>2,'v3'=>3,'v4'=>5);

How do I merge them to a single array like this :

Array
(
    [v1] => 1
    [v2] => 2
    [v3] => 3
    [v4] => Array
        (
            [0] => 4
            [1] => 5
        )
)

I have tried using array_merge & array_merge_recursive.

I don't think there's any built-in command that does what you want in a shot... — Andreas Wong
– Andreas Wong, Commented May 25, 2012 at 8:23
I am not looking for one either, I am just looking for the shortest way possible. — karth
– karth, Commented May 25, 2012 at 8:26

anubhava · Accepted Answer · 2012-05-25 08:30:03Z

3

You can use this code:

$a = array('v1'=>1,'v2'=>2,'v3'=>3,'v4'=>4);
$b = array('v1'=>1,'v2'=>2,'v3'=>3,'v4'=>5);
$c = array();
foreach($a as $m => $n) {
   if (($b[$m] != $n))
      $c[$m] = array($n, $b[$m]);
   else
      $c[$m] = $n;
}

answered May 25, 2012 at 8:30

anubhava

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Comments

flowfree · Accepted Answer · 2012-05-25 08:47:49Z

3

$result = array_intersect_assoc($a, $b);

foreach (array_diff_assoc($a, $b) as $k => $v)
  $result[$k] = array($v, $b[$k]);

Update:
anubhava's solution is good. It can be simplified like this:

$c = array();
foreach($a as $k => $v) 
  $c[$k] = $b[$k] == $v ? $v : array($v, $b[$k]);

edited May 25, 2012 at 8:47

answered May 25, 2012 at 8:38

flowfree

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Comments

Samy Dindane · Accepted Answer · 2012-05-25 08:34:18Z

1

$a = array('v1'=>1,'v2'=>2,'v3'=>3,'v4'=>4);
$b = array('v1'=>1,'v2'=>2,'v3'=>3,'v4'=>5);
$results = array();

foreach ($a as $key=>$elem) {
  $results[$key][] = $elem;
  if (!in_array($b[$key], $results[$key])) {
    $results[$key][] = $b[$key];
  }
}

edited May 25, 2012 at 8:34

answered May 25, 2012 at 8:26

Samy Dindane

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2 Comments

Samy Dindane Over a year ago

Yeah sorry, didn't notice that.

Gavriel Over a year ago

still not, see @anubhava's solution

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