Simple PHP lambda example

app.php

<?php

$books = [
    [
        'name' => 'Earth 1',
        'author' => 'Andrew',
        'pubDate' => '2024-03-08'
    ],
    [
        'name' => 'Earth 3',
        'author' => 'Andrew',
        'pubDate' => '2023-02-18'
    ],
    [
        'name' => 'Lorem',
        'author' => 'Andy',
        'pubDate' => '2021-03-18'
    ]
];

function filter($items, $fn) {
    $filteredItems = [];

    foreach ($items as $item) {
        if ($fn($item)) {
            $filteredItems[] = $item;
        }
    }

    return $filteredItems;
}

$output = filter($books, function ($book) {
    return $book['author'] === 'Andrew';
});

print_r($output);
/*
Array
(
    [0] => Array
        (
            [name] => Earth 1
            [author] => Andrew
            [pubDate] => 2024-03-08
        )

    [1] => Array
        (
            [name] => Earth 3
            [author] => Andrew
            [pubDate] => 2023-02-18
        )

)
*/