PHP recreate array if it contains certain values - php

Question

I have $fruits_arr:
Array
(
[0] => Array
(
[id] => 213
[fruit] => banana
)
[1] => Array
(
[id] => 438
[fruit] => apple
)
[2] => Array
(
[id] => 154
[fruit] => peach
)
)
And $ids_arr:
Array (
[0] => 213
[1] => 154
)
I want to recreate $fruits_arr to have only array items where id is equal to a value from $ids_arr. I also want to maintain the index/array order of $fruits_arr.
I'm using the following:
$selected_fruits = array();
foreach( $fruits_arr as $fruit ) :
if ( in_array( $fruit['id'], $ids_arr ) ) :
$selected_fruits[] = $fruit;
endif;
endforeach;
print_r( $selected_fruits );
It seems to work but I am wondering if there is a shorter, better way to accomplish this in the latest PHP version.

Answer 1

This is not a shorter or newer way, but perhaps instead of performing in_array for every iteration, you could use array_flip and then use isset to check for the key:
$ids_arr = array_flip($ids_arr);
$selected_fruits = [];
foreach ($fruits_arr as $k => $fruit) {
if (isset($ids_arr[$fruit["id"]])) {
$selected_fruits[$k] = $fruit;
}
}
Php demo

Answer 2

You could use array_filter to make it more concise, but it will not be much and could make your code less readable. If possible chose readability over length of code.
$selected_fruits = array_filter($fruits_arr, function ($el) use ($ids_arr) {
return in_array($el['id'], $ids_arr, true);
});
or you can wait for PHP 7.4 (due to come out at the end of the year) and use arrow functions.
$selected_fruits = array_filter($fruits_arr, fn ($el) => in_array($el['id'], $ids_arr, true));
Demo: https://3v4l.org/4UC41

Answer 3

If the array is associative (use array_column for that) then you can use array_intersect_key to do the job.
$fruits_arr = array_column($fruits_arr, Null, "id");
$result = array_intersect_key($fruits_arr, array_flip($ids_arr));
var_dump($result);
https://3v4l.org/jQo6E

Answer 4

Keeping it simple, a loop where you remove items that are not in your keep array.
<?php
$fruits =
[
'foo' => [
'id' => 1,
'fruit' => 'banana'
],
'bar' => [
'id' => 2,
'fruit' => 'orange'
],
'baz' => [
'id' => 3,
'fruit' => 'pear'
],
];
$keep_ids = [1,3];
foreach($fruits as $k=>$v)
if(!in_array($v['id'], $keep_ids))
unset($fruits[$k]);
var_export($fruits);
Output:
array (
'foo' =>
array (
'id' => 1,
'fruit' => 'banana',
),
'baz' =>
array (
'id' => 3,
'fruit' => 'pear',
),
)