haphpiness

array_map, array_filter, array_reduce — The Functional Trio

PHP's array functions have always been powerful, but with arrow functions (7.4) and first-class callables (8.1), they've become genuinely elegant. Transform, filter, and reduce collections without a single foreach loop.

$orders = getOrders();

// Transform: extract what you need
$totals = array_map(fn($o) => $o->total, $orders);

// Filter: keep what matches
$large = array_filter($orders, fn($o) => $o->total > 100);

// Reduce: collapse to a single value
$sum = array_reduce($orders, fn($carry, $o) => $carry + $o->total, 0);

// Compose them for expressive pipelines
$report = array_reduce(
    array_map(
        fn($o) => ['month' => $o->date->format('Y-m'), 'total' => $o->total],
        array_filter($orders, fn($o) => $o->status === Status::Completed),
    ),
    function ($acc, $item) {
        $acc[$item['month']] = ($acc[$item['month']] ?? 0) + $item['total'];
        return $acc;
    },
    [],
);

// Plus the underrated helpers:
$keys     = array_keys($map);
$values   = array_values($filtered);  // Re-index after filter
$combined = array_combine($keys, $values);
$unique   = array_unique($tags);
$chunks   = array_chunk($items, 50);   // Batch processing

PHP arrays are ordered hash maps — they work as lists, dictionaries, sets, stacks, and queues. The standard library gives you phparray_map, phparray_filter, phparray_reduce, and 75+ other array functions out of the box.