Online PHP editor | perf for 2kHVL

<?php // Source - https://stackoverflow.com/a/9276284 // Posted by kingmaple, modified by community. See post 'Timeline' for change history // Retrieved 2026-04-08, License - CC BY-SA 4.0 // Source - https://stackoverflow.com/a/53203232 // Posted by slaszu, modified by community. See post 'Timeline' for change history // Retrieved 2026-04-08, License - CC BY-SA 4.0 // ini_set('memory_limit', '2048M'); function formatBytes(int $bytes): string { $units = ['B', 'KB', 'MB', 'GB']; $i = 0; while ($bytes >= 1024 && $i < count($units) - 1) { $bytes /= 1024; $i++; } return sprintf("%.2f %s", $bytes, $units[$i]); } function benchmark(callable $fn, string $label): array { gc_collect_cycles(); gc_mem_caches(); memory_reset_peak_usage(); $mem = -memory_get_peak_usage(); $time = -hrtime(true); $fn(); $time += hrtime(true); $mem += memory_get_peak_usage(); return [ 'label' => $label, 'time_ms' => $time / 1e6, 'mem_used' => $mem, ]; } function manual_intersect($arrayOne, $arrayTwo) { $index = array_flip($arrayOne); foreach ($arrayTwo as $value) { if (isset($index[$value])) { unset($index[$value]); } } foreach ($index as $value => $key) { unset($arrayOne[$key]); } return $arrayOne; } function flipped_intersect($arrayOne, $arrayTwo) { $index = array_flip($arrayOne); $second = array_flip($arrayTwo); $x = array_intersect_key($index, $second); return array_flip($x); } function runBenchmarks(int $n): void { echo "\n=== Array Intersection Benchmark for " . number_format($n) . " elements ===\n"; // Generate test arrays $one = []; $two = []; for ($i = 0; $i < $n; $i++) { $one[] = rand(0, 1000000); $two[] = rand(0, 100000); $two[] = rand(0, 10000); } $one = array_unique($one); $two = array_unique($two); $results = []; $results[] = benchmark( fn() => $res = array_intersect($one, $two), 'array_intersect()' ); $results[] = benchmark( fn() => $res = manual_intersect($one, $two), 'manual_intersect()' ); $results[] = benchmark( fn() => $res = flipped_intersect($one, $two), 'flipped_intersect()' ); // --- Print Table --- echo str_repeat('-', 60) . "\n"; printf("%-25s | %-14s | %-15s\n", 'Method', 'Time (ms)', 'Memory'); echo str_repeat('-', 60) . "\n"; foreach ($results as $r) { printf("%-25s | %11.3f ms | %15s\n", $r['label'], $r['time_ms'], formatBytes($r['mem_used']) ); } echo str_repeat('-', 60) . "\n"; } // Run for various sizes foreach ([20, 20000, 200000] as $n) { runBenchmarks($n); }

Version	System time (s)	User time (s)	Memory (MiB)
8.5.3	0.080	0.297	43.90
8.5.2	0.066	0.295	43.87
8.5.1	0.058	0.303	43.97
8.5.0	0.057	0.293	43.68
8.4.18	0.035	0.085	45.24
8.4.17	0.039	0.084	45.17
8.4.16	0.040	0.095	44.98
8.4.15	0.026	0.074	45.31
8.4.14	0.051	0.304	45.05
8.4.13	0.045	0.303	45.12
8.4.12	0.046	0.310	45.16
8.4.11	0.069	0.320	45.14
8.4.10	0.057	0.301	44.96
8.4.9	0.051	0.305	45.20
8.4.8	0.061	0.308	45.18
8.4.7	0.054	0.323	44.98
8.4.6	0.049	0.302	45.16
8.4.5	0.062	0.313	45.23
8.4.4	0.054	0.296	45.02
8.4.3	0.061	0.307	44.91
8.4.2	0.065	0.301	45.01
8.4.1	0.054	0.306	45.07
8.3.30	0.040	0.071	43.57
8.3.29	0.031	0.075	43.49
8.3.28	0.045	0.070	43.27
8.3.27	0.061	0.299	44.03
8.3.26	0.054	0.304	44.13
8.3.25	0.058	0.296	43.89
8.3.24	0.049	0.298	43.93
8.3.23	0.070	0.306	44.43
8.3.22	0.070	0.304	44.21
8.3.21	0.053	0.293	44.07
8.3.20	0.072	0.282	43.95
8.3.19	0.061	0.307	43.77
8.3.18	0.057	0.294	44.03
8.3.17	0.054	0.287	43.96
8.3.16	0.053	0.302	44.61
8.3.15	0.045	0.303	44.09
8.3.14	0.048	0.301	44.09
8.3.13	0.046	0.307	44.04
8.3.12	0.060	0.324	44.00
8.3.11	0.054	0.306	44.05
8.3.10	0.056	0.297	44.11
8.3.9	0.065	0.301	43.87
8.3.8	0.072	0.312	44.01
8.3.7	0.057	0.291	44.11
8.3.6	0.047	0.314	44.57
8.3.5	0.067	0.293	44.27
8.3.4	0.029	0.053	34.03
8.3.3	0.035	0.074	33.96
8.3.2	0.023	0.058	34.12
8.3.1	0.041	0.069	33.84
8.3.0	0.024	0.058	34.11