Merge array by index/key keeping all values

Question

I have n number of arrays

$array1=array('usa'=>123, 'uk' => '1234', 'germany'=> '1235');
$array2=array('usa'=>123a, 'uk' => '1234', 'germany'=> '1235aa');
$array3=array('usa'=>123, 'uk' => '1234a', 'germany'=> '123a5');

$arrayn=array('usa'=>123b, 'uk' => '1234', 'germany'=> '1235');

I need a php code so that I can have result as follows:

$final_array=array(
                 'usa'=>'123,123a,123,...,123b',
                 'uk'=>'1234,1234,1234a,...,1234', 
                 'germany'=>'1235,1235aa, 123a5,...,1235'
             );

Can anyone help me how to do this?

the $array1 to $arrayn are not on array? Are they individual variables? — Eddie, May 19 '14 at 07:18
@user1140176 : To get some idea from [this](http://stackoverflow.com/questions/14842272/php-array-merge-two-arrays-on-same-key#answer-14843843) tutorial. — Ranjith, May 19 '14 at 07:23
@UglyEddie : It may `static` or `dynamic`. That's not necessary here. He need some logic to merge both of them. Simple. — Ranjith, May 19 '14 at 07:26
@UglyEddie The number of arrays varies and the element inside also varies — user1140176, May 19 '14 at 07:26
@Ranjith, yes it would matter. Please look at the answers below. They are on the fixed (static) 3 variables only. So those answers needed modification. Simple. — Eddie, May 19 '14 at 07:36
@user1140176, please check my response below. It can handle $array1 to $arrayn — Eddie, May 19 '14 at 08:01

score 2 · Accepted Answer · answered May 19 '14 at 07:22

2

So use call_user_func_array() to do this:

$array1=array('usa'=>'123', 'uk' => '1234', 'germany'=> '1235');
$array2=array('usa'=>'123a', 'uk' => '1234', 'germany'=> '1235aa');
$array3=array('usa'=>'123', 'uk' => '1234a', 'germany'=> '123a5');

$result = array_map(function($x)
{
   return join(',', $x);
}, call_user_func_array('array_merge_recursive', [$array1, $array2, $array3]));

That is: array_merge_recursive() will gather all the items with corresponding key. Later array_map() will use join() to transform items to delimiter-separated strings.

Note, that, since all your arrays are separated variables, you'll have to re-count all of them in parameters array for call_user_func_array()

answered May 19 '14 at 07:22

Alma Do

37,009
9
76
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What if I have to pass n number of arrays. I mean what if i dont know how many arrays are there?? – user1140176 May 19 '14 at 07:44
Then create array, which will contain your arrays. Because if you have some set of variables and you don't know what they are (what are their names, what are their count e t.c.) - then how can you get the result? Your input conditions should be defined, you can not do it with "unknown variables" – Alma Do May 19 '14 at 07:46

score 1 · Answer 2 · answered May 19 '14 at 07:29

You can create a function, where you can pass your arrays one by one.

<?php
$array1=array('usa'=>'123', 'uk' => '1234', 'germany'=> '1235');
$array2=array('usa'=>'123a', 'uk' => '1234', 'germany'=> '1235aa');
$array3=array('usa'=>'123', 'uk' => '1234a', 'germany'=> '123a5');

function add_arr($arr, &$final)
{
    foreach($arr as $key=>$val){
        if(isset($final[$key])){
            $final[$key].=",".$val;
        }else{
           $final[$key]=$val;
        }
    }
}

$arr_final=array();
add_arr($array1,$arr_final);
add_arr($array2,$arr_final);
add_arr($array3,$arr_final);

print_r($arr_final);
?>

Here is DEMO

score 1 · Answer 3 · answered May 19 '14 at 07:37

function array_merge_multiple() {
    $result = array();
    $numargs = func_num_args();
    $arg_list = func_get_args();
    for ($i = 0; $i < $numargs; $i++) {
        $array = $arg_list[$i];
        $keys = array_keys($array);
        foreach ($keys as $v) {
            if (isset($result[$v])) {
                $result[$v].="," . $array[$v];
            } else {
                $result[$v] = $array[$v];
            }
        }
    }
    return $result;
}
$result=array_merge_multiple($array1,$array2,$array3,$arrayn);

//$result=array_merge_multiple($array1,$array2,$array3,.........,$arrayn);

print_r($result);

this will produce your expected result, your can pass "N" Number of array. — Nanhe Kumar, May 19 '14 at 07:50

score 0 · Answer 4 · answered May 19 '14 at 07:22

Something like this perhaps

function black_magic($arrays = array()) {
$return = array();
foreach ($arrays as $array) {
    if (!$return) {
    $return = $array;
    continue;
    }

    foreach ($array as $key => $value) {
    if (isset($return[$key])) {
        $return[$key] .= ($return[$key]) ? ",$value" : $value;
    }
    else {
        $return[$key] = $value;
    }

    unset($key, $value);
    }

    unset($array);
}

return $return;
}

score 0 · Answer 5 · answered May 19 '14 at 07:28

0

You can do something like this:

$array1=array('usa'=>123, 'uk' => '1234', 'germany'=> '1235');

$array3=array('usa'=>1231, 'uk' => '1234a', 'germany'=> '123a5');

$result = array_merge_recursive($array1, $array3);

$result being the merged results

answered May 19 '14 at 07:28

Hamster

680
7
23

Merge array by index/key keeping all values

5 Answers5