PHP : merge two arrays, but keep only keys from the first one

Question

I've got this method which merges two arrays, like this :

<?php
$array1 = [
    'huey' => 0,
    'dewey' => 1,
    'louie' => 2
];

$array2 = [
    'dewey' => 3,
    'beagle boys' => '  167-671'
];

$array3 = array_merge($array1, $array2);

var_dump($array3);

The problem is, even if the key "dewey" is updated, I don't want my array to have the "beagle boys" key. How can I update my code to output only keys which are on the first array ?

Use what you have now in combination with [array_unique](http://php.net/array_unique) - the order in which you pass the arrays to this function does matter, so careful with that. — Andrei, Jul 13 '16 at 14:23
@iainn looks like the same, I'm checking its answers. Thanks ! — Marc Brillault, Jul 13 '16 at 14:27
From the other answer: you will need two operations to do this -- one is to get the keys you need from `$array2`. Compute the intersection. Then, you can do the merge. — Explosion Pills, Jul 13 '16 at 14:27

score 3 · Accepted Answer · answered Jul 13 '16 at 14:29

3

$array3 = array_merge(
    $array1,
    array_intersect_key($array2, $array1)
);

answered Jul 13 '16 at 14:29

u_mulder

54,101
5
48
64

Thanks ! On the duplicate subject, another answer is also possible : array_intersect_key($array2, $array1) + $array1 – Marc Brillault Jul 13 '16 at 14:32

score 0 · Answer 2 · answered Jul 13 '16 at 14:27

0

Copy only data from array2 which exists in array1

$array1 = [
    'huey' => 0,
    'dewey' => 1,
    'louie' => 2
];

$array2 = [
    'dewey' => 3,
    'beagle boys' => '  167-671'
];

$array3 = $array1;

foreach ($array1 as $key => $values){
  if (isset($array2[$key])) {
    $array3[$key] = $array2[$key];
  }
}

print_r($array3);

answered Jul 13 '16 at 14:27

nospor

4,190
1
16
25

Thanks for your answer, but I was looking for something a bit neater (Should have said it in the subjec though). – Marc Brillault Jul 13 '16 at 14:34
@MarcBrillault Yes, another answer is neater :) – nospor Jul 13 '16 at 14:37

PHP : merge two arrays, but keep only keys from the first one

2 Answers2