PHP array_filter 获取没有键的值

Question

I come from a Javascript background, and I am trying to use array_filter() , but it works quite different from JS.

Taking this JS example:

const people = [
  {
    name: 'Will',
    username: 'will',
  },
  {
    name: 'Alex',
    username: 'alex',
  },
  {
    name: 'Abraham',
    username: 'abraham',
  },
];

const usernameToFind = 'abraham';

const found = people.filter(person => person.username === usernameToFind);

console.log(found[0]); // index 0

// {
//   name: 'Abraham',
//   username: 'abraham'
// }

I expect all the usernames to be different, so it is always going to return only one value. So if I want to access the information found I just ask for index 0 .

On PHP:

<?php

$people = [
  [
    'name' => 'Alex',
    'username' => 'alex',
  ],
  [
    'name' => 'Will',
    'username' => 'will',
  ],
  [
    'name' => 'Abraham',
    'username' => 'abraham',
  ],
];

$usernameToFind = 'abraham';

$found = array_filter($people, function($person) use ($usernameToFind) {
  return $person['username'] === $usernameToFind;
});

print_r($found);

// Array
// (
//     [2] => Array
//         (
//             [name] => Abraham
//             [username] => abraham
//         )
// )

So my issue is: I get an array with the index of the element found, but I don't know what the index is.

I saw this question but it is quite different: PHP array_filter to get only one value from an array .

I am not using array_search() , because my needle to search is 2 or 3 levels deep like:

array_filter($people, function ($person) use ($cityToFind) {
   return $person['location']['city'] === $cityToFind;
}

I can use a for loop, but I really wanted to use filter instead. Thanks in advance!

Answer 1

You can do a couple things.

1. To get the first element of the array you can use reset($found) https://www.php.net/manual/en/function.reset.php

2. After filtering the array you can reset the array keys to start at 0 using array_values($found) https://www.php.net/manual/en/function.array-values.php

Answer 2

Using array_filter() will always process the entire array, in your example it's the last entry so it needs to anyway. But if you had 500 entries and it was the first 1, it will still check all 500 entries.

Instead you could use a simple foreach() loop which stops as soon as it finds the first one...

foreach ( $people as $index => $person )    {
    if ( $person['username'] === $usernameToFind )  {
        echo "Index={$index} name={$person['name']}";
        break;
    }
}

gives...

Index=2 name=Abraham

As an answer to your original question - you can use After array_filter(), how can I reset the keys to go in numerical order starting at 0 to reset the keys so you can use [0] .