How to prevent spread operator to change the original array?-CodePudding

I am having two arrays in php 7.4.16

$data_one = array(
    ['id' => 491, 'default' => false],
    ['id' => 492, 'default' => false],
    ['id' => 493, 'default' => true],
);

and

$data_two = array(
    ['id' => 491, 'default' => false],
    ['id' => 492, 'default' => true],
    ['id' => 493, 'default' => false],
    ['id' => 494, 'default' => false],
);

I am using the spread operator:

$data_one = [...$data_two];

is adding the missing array with id 494 to $data_one .... but also is overwriting the value for "default" in the $data_one. (in the first array with id 492 the default will become true, and id 493 will become false)

How can I add the new entries from $data_two to $data_one but keep the original values ("default") from $data_one ?

** UPDATE **

the final array should look like this

$data_one = array(
    ['id' => 491, 'default' => false],
    ['id' => 492, 'default' => false],
    ['id' => 493, 'default' => true],
    ['id' => 494, 'default' => false],
);

CodePudding user response：

Loop through the elements in $data_two. Check if its id already exists in $data_one. If not, add it.

$ids = array_column($data_one, 'id');
foreach ($data_two as $item) {
    if (!in_array($item['id'], $ids)) {
        $data_one[] = $item;
    }
}

CodePudding user response：

Use the spread operator (array_merge() on array values only, surrogate for array_values()) with the array union operator over the id-indexed $data_one and $data_two arrays with $data_two being on the right-hand side:

$id = 'id';
$idx = static fn(array $data) => array_column($data, null, $id);

$result = [
    ... $idx($data_one)
        $idx($data_two)
];

Only the values of new entities (identity by their id) are appended.

All ids should be integers.

If you're not interested in the resulting array keys, you can also keep them:

$id = 'id';
$idx = static fn(array $data) => array_column($data, null, $id);

$result = $idx($data_one)
          $idx($data_two)
        ;

And a more generic PHP code example on 3v4l.org: https://3v4l.org/2Lk8R (PHP 5.5 variant).