Randomness distribution test of different random functions

randomness.php

#!/usr/bin/env php
<?php

/**
 * Randomness distribution test of different random functions
 */

$counters = [
    'array_rand' => [],
    'random_int' => [],
];

foreach ($counters as $name => &$items) {
    for ($i=0; $i < 4; $i++) { 
        $items['item' . $i] = 0;
    }
}

$runLoop = function ($function, $items) use (&$counters)
{
    for ($i=0; $i < 1000000; $i++) {
        switch ($function) {
            case 'array_rand':
                $key = $function($items);
                $counters[$function][$key]++;
                break;

            case 'random_int':
                $keys = array_keys($items);
                $index = random_int(0, count($keys) - 1);
                $counters[$function][$keys[$index]]++;
                break;

            default:
                break;
        }        
    }
};

foreach ([
    'array_rand',
    'random_int',
] as $function) {
    $runLoop($function, $counters[$function]);
}

print_r($counters);