How to merge two arrays in php?

Question

I have the following arrays which I'd like to combine / merge to create a single array that I can loop through to add images and their respective titles to a database.

Array 1:

[0] => array(1) {
  ["filename"] => string(22) "1463668615_1_image.jpg"
}
[1] => array(1) {
  ["filename"] => string(22) "1463668641_1_image.jpg"
}

Array 2:

[0] => array(1) {
  ["title"] => string(15) "My image title"
}
[1] => array(1) {
  ["title"] => string(5) "Title"
}

Here's the format of the array I'd like to create.

Merged Arrays:

[0] => array(2) {
  ["filename"] => string(22) "1463668615_1_image.jpg",
  ["title"] => string(3) "My image title"
}
[1] => array(2) {
  ["filename"] => string(22) "1463668641_1_image.jpg",
  ["title"] => string(0) "Title"
}

What? Why do the titles end up as "MFH" and an empty string? — Jonnix, May 19 '16 at 14:55
Have you even googled this? First result - http://php.net/manual/en/function.array-merge.php — Styphon, May 19 '16 at 14:56
@Styphon And you'd expect that to work on multi-dimensional arrays? — Jonnix, May 19 '16 at 14:58
@JonStirling Yes, I would. If you read the documentation it says it does. — Styphon, May 19 '16 at 15:31
@Styphon And if you read the documentation, you will find that it doesn't do what OP is asking. — Jonnix, May 19 '16 at 15:34
@JonStirling - Sorry. The titles in my merged arrays snippet were wrong. I've corrected them now. — Jim Pannell, May 20 '16 at 07:21
@Styphon Thanks for your input - I tried that and couldn't get it to do what I wanted. — Jim Pannell, May 20 '16 at 07:23

score 2 · Answer 1 · answered May 19 '16 at 15:25

If I understand you correctly this called zip, not merge. You can do this with array_map() function:

$filenames = [
    ['filename' => '1463668615_1_image.jpg'],
    ['filename' => '1463668641_1_image.jpg']
];

$titles = [
    ['title' => 'Title1'],
    ['title' => 'Title2']
];

$zipped = array_map(function ($elem1, $elem2) {
    return [
        'filename' => $elem1['filename'],
        'title' => $elem2['title']
    ];
}, $filenames, $titles);

var_dump($zipped);

Here is demo.

score 2 · Accepted Answer · answered May 19 '16 at 15:27

2

array_merge() is the way just use it as the callback in array_map():

$result = array_map('array_merge', $array1, $array2);

answered May 19 '16 at 15:27

AbraCadaver

78,200
7
66
87

Peon · Answer 3 · 2016-05-19T15:43:21.487

1

Will the structure of the arrays be the same? And will the size of those arrays also always be the same? If not, there is no sure way to do this, if yes, you can do a simple loop:

$arr1 = array(
    0 => array(
        "filename" => "1463668615_1_image.jpg",
    ),
    1 => array(
        "filename" => "1463668641_1_image.jpg",
    ),
);

$arr2 = array(
    0 => array(
        "title" => "My image title",
    ),
    1 => array(
        "title" => "Title",
    ),
);

$new = array();
for ($k = 0, $size = count($arr1); $k < $size; $k++) {
    $new[$k]['filename'] = $arr1[$k]['filename'];
    $new[$k]['title'] = $arr2[$k]['title'];
}

var_dump($new);

edited May 19 '16 at 15:43

answered May 19 '16 at 15:00

Peon

7,902
7
59
100

@Daninis Put the count outside the loop, it's an unnecessary overhead! – Edward May 19 '16 at 15:25
I declined your edit, since it was not, what I intended to show. You can check the manual here: http://php.net/manual/en/control-structures.for.php – Peon May 19 '16 at 15:33
yes either way will do, I prefer to set the variable explicitly outside the loop because it's more readable but my 'Wait for it...' point was you are comparing `$i` not `$k` you rebel! – Edward May 19 '16 at 15:37
@DainisAbols I would hope you test your own code. Its your answer not mine. – CodeGodie May 19 '16 at 15:45

Sofiene Djebali · Answer 4 · 2016-05-19T15:08:47.500

0

This should work :

PHP

    $filenames = [["filename" => "1463668615_1_image.jpg"], ["filename" => "146366865213_image.jpg"]];
    $titles = [["title" => "Titre1"], ["title" => "Titre22"]];

    foreach ($filenames as $key => &$value) {
         $value['title'] = $titles[$key]['title'];
    }

    var_dump($filenames);

edited May 19 '16 at 15:08

answered May 19 '16 at 14:58

Sofiene Djebali

4,398
1
21
27

How to merge two arrays in php?

4 Answers4