Test arrays comparasion

compare_arrays.php

<?php

// test variants
$array_first  = ["a" => "green", "b" => "brown", "c" => "blue", "red", "array", "array_search", "test"];
$array_second = ["a" => "green", "b" => "yellow", "red", "array_search", "blue", "benchmark"];

test('compare1', $array_first, $array_second);
test('compare2', $array_first, $array_second);
test('compare3', $array_first, $array_second);
test('compare4', $array_first, $array_second);

// generate random values
$count = 100;

$array_first_values = [];
$array_second_values = [];

for ($n = 0; $n < $count; $n++) {
    for ($i = 0; $i < 1000; $i++) {
        $array_first_values[$n][$i] = str_shuffle('abcdefg'); // 7! = 5040
    }

    for ($i = 0; $i < 1000; $i++) {
        $array_second_values[$n][$i] = str_shuffle('abcdefg');
    }
}

run('compare1', $array_first_values, $array_second_values);
run('compare2', $array_first_values, $array_second_values);
run('compare3', $array_first_values, $array_second_values);
run('compare4', $array_first_values, $array_second_values);


function test($func, $array_first, $array_second)
{
    $expected = [
        'green' => ['a', 'a'],
        'blue' => ['c', 2],
        'red' => [0, 0],
        'array_search' => [2, 1],
    ];
    $res = $func($array_first, $array_second);

    echo $func . ': ';
    if ($res === $expected) {
        echo 'pass';
    } else {
        echo 'ERROR';
    }
    echo PHP_EOL;
}

function run($func, $array_first_values, $array_second_values)
{
    $count = count($array_first_values);
    $start_time = microtime(true);

    for ($i = 0; $i < $count; $i++) {
        $func($array_first_values[$i], $array_second_values[$i]);
    }

    echo $func . ': ' . (microtime(true) - $start_time) . 's' . PHP_EOL;
}


function compare1($array_first, $array_second)
{
    $res = [];
    foreach ($array_first as $key => $value) {
        if (in_array($value, $array_second, true)) {
            $key_second = array_search($value, $array_second, true);
            $res[$value] = [$key, $key_second];
        }
    }

    return $res;
}

function compare2($array_first, $array_second)
{
    $res = [];
    foreach ($array_first as $key => $value) {
        $key_second = array_search($value, $array_second, true);
        if ($key_second !== false) {
            $res[$value] = [$key, $key_second];
        }
    }

    return $res;
}

function compare3($array_first, $array_second)
{
    $res = [];
    $array_second_rev = array_flip($array_second);

    foreach ($array_first as $key => $value) {
        if (isset($array_second_rev[$value])) {
            $res[$value] = [$key, $array_second_rev[$value]];
        }
    }

    return $res;
}

function compare4($array_first, $array_second)
{
    $res = [];

    $ar1 = array_intersect($array_first, $array_second);
    $ar2 = array_intersect($array_second, $array_first);

    foreach ($ar1 as $key => $value) {
        $key_second = array_search($value, $ar2, true);
        if ($key_second !== false) {
            $res[$value] = [$key, $key_second];
        }
    }

    return $res;
}