Merge, chunk, then transpose and flatten data from multiple indexed arrays

Question

I have three arrays:

$a = ['a1', 'a2', 'a3', 'a4', 'a5', 'a6', 'a7', 'a8', 'a9', 'a10'];
$b = ['b1', 'b2', 'b3', 'b4', 'b5', 'b6', 'b7', 'b8', 'b9', 'b10'];
$c = ['c1', 'c2', 'c3', 'c4', 'c5', 'c6', 'c7', 'c8', 'c9', 'c10'];

I want to combine these arrays to create:

$new1 = (a1, a2, b1, b2, c1, c2);

$new2 = (a3, a4, b3, b4, c3, c4);

$new3 = (a5, a6, b5, b6, c5, c6);

$new4 = (a7, a8, b7, b8, c7, c8);

$new5 = (a9, a10, b9, b10, c9, c10);

How to make it like that?

What have you tried so far? And what does this have to do with `laravel`? — Nick, Mar 21 '19 at 03:10
We need to see the related PHP code so we can try to determine where your error is. Please edit your question to include the code. (thx) — elbrant, Mar 21 '19 at 05:35

score 1 · Accepted Answer · answered Mar 21 '19 at 03:29

You, you would want to map each array into it's chunked version using array_map and array_chunk, so that you get them in 2 element arrays. Then, you would want to reduce those so that each chunk goes in the same final array, for which you would use array_reduce:

$a = array('a1', 'a2', 'a3', 'a4', 'a5', 'a6', 'a7', 'a8', 'a9', 'a10');
$b = array('b1', 'b2', 'b3', 'b4', 'b5', 'b6', 'b7', 'b8', 'b9', 'b10');
$c = array('c1', 'c2', 'c3', 'c4', 'c5', 'c6', 'c7', 'c8', 'c9', 'c10');

$final = array_reduce(array_map(function($el) {
             return array_chunk($el, 2);
         }, [$a, $b, $c]), function($carry, $item) {
             foreach($item as $key => $value) {
                 if (!isset($carry[$key])) {
                     $carry[$key] = [];
                 }
                 $carry[$key] = array_merge($carry[$key], $value);
             }
             return $carry;
         });

$new1 = $f[0];
$new2 = $f[1];
$new3 = $f[2];
$new4 = $f[3];
$new5 = $f[4];

var_dump($f);
/*
 array(5) {
  [0]=>
  array(6) {
    [0]=>
    string(2) "a1"
    [1]=>
    string(2) "a2"
    [2]=>
    string(2) "b1"
    [3]=>
    string(2) "b2"
    [4]=>
    string(2) "c1"
    [5]=>
    string(2) "c2"
  }
  [1]=>
  array(6) {
    [0]=>
    string(2) "a3"
    [1]=>
    string(2) "a4"
    [2]=>
    string(2) "b3"
    [3]=>
    string(2) "b4"
    [4]=>
    string(2) "c3"
    [5]=>
    string(2) "c4"
  }
  [2]=>
  array(6) {
    [0]=>
    string(2) "a5"
    [1]=>
    string(2) "a6"
    [2]=>
    string(2) "b5"
    [3]=>
    string(2) "b6"
    [4]=>
    string(2) "c5"
    [5]=>
    string(2) "c6"
  }
  [3]=>
  array(6) {
    [0]=>
    string(2) "a7"
    [1]=>
    string(2) "a8"
    [2]=>
    string(2) "b7"
    [3]=>
    string(2) "b8"
    [4]=>
    string(2) "c7"
    [5]=>
    string(2) "c8"
  }
  [4]=>
  array(6) {
    [0]=>
    string(2) "a9"
    [1]=>
    string(3) "a10"
    [2]=>
    string(2) "b9"
    [3]=>
    string(3) "b10"
    [4]=>
    string(2) "c9"
    [5]=>
    string(3) "c10"
  }
}

prasanth · Answer 2 · 2019-03-21T03:56:09.903

You need add all array in one array

Then applied while loop with count of $a/2
Then use array_map return with iterated index value plus one .its means if is 0 its get a1,a2 value respectively .
Then finally merge array and pass with result array

Sandbox Test

$a = Array('a1', 'a2', 'a3', 'a4', 'a5', 'a6', 'a7', 'a8', 'a9', 'a10');
$b = Array('b1', 'b2', 'b3', 'b4', 'b5', 'b6', 'b7', 'b8', 'b9', 'b10');
$c = Array('c1', 'c2', 'c3', 'c4', 'c5', 'c6', 'c7', 'c8', 'c9', 'c10');
$arr = [$a,$b,$c];
$i=0;
$res=[];
while($i < (count($a)/2)){
    $res[$i]=call_user_func_array('array_merge',array_map(function($ar=[]) use ($i){
       return [$ar[$i],$ar[$i+1]];
    },$arr));
    $i++;
}
print_r($res);
print_r($res[0]);
$new1=$res[0];
$new2=$res[1];
$new3=$res[2];

print_r($new1);
print_r($new2);
print_r($new3);

mickmackusa · Answer 3 · 2022-09-27T10:34:54.843

Here is a fully functional-style approach that will accept any number of arrays. It is assumed that your input arrays will have the same length. Because my approach is so flexible, it does not produce hardcoded, individual variables as its result.

Form a single array from all input arrays, then
Chunk each input array's data, then
Transpose and flatten the chunks.

Code: (Demo)

var_export(
    array_map(
        fn(...$cols) => array_merge(...$cols),
        ...array_map(
            fn($row) => array_chunk($row, 2),
            [$a, $b, $c]
        )
    )
);

Merge, chunk, then transpose and flatten data from multiple indexed arrays

3 Answers3