PHP code example of antikirra / probability

1. Go to this page and download the library: Download antikirra/probability library. Choose the download type require.

2. Extract the ZIP file and open the index.php.

3. Add this code to the index.php. 
    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

antikirra / probability example snippets


probability(0.25); // 25% chance, different result each time


probability(0.25, 'unique_key'); // Same result for same key


function probability(float $probability, string $key = ''): bool


// 15% random chance
probability(0.15);

// Deterministic 30% for user with id 123
probability(0.30, "user_123");

// Combining feature and user for unique distribution
probability(0.25, "feature_checkout_user_123");


// ❌ Bad - too generic
probability(0.5, "test");

// ✅ Good - specific and unique
probability(0.5, "homepage_redesign_user_$userId");


// ❌ Bad - same users get all features
if (probability(0.2, $userId)) { /* feature A */ }
if (probability(0.2, $userId)) { /* feature B */ }

// ✅ Good - different user groups per feature
if (probability(0.2, "feature_a_$userId")) { /* feature A */ }
if (probability(0.2, "feature_b_$userId")) { /* feature B */ }


// For high-frequency operations, use very small probabilities
if (probability(0.001)) { // 0.1% - suitable for millions of requests
    $metrics->record($data);
}