is checking an array_key faster than disabling E_NOTICE

noticetest

PHP Version 5.4.30

-------------------------------------------------------
Testing 10 item array over 100,000 iterations:

isset                                   18.280982971191
array_key_exists                        96.060037612915
^E_NOTICE                               71.103811264038
-------------------------------------------------------
Testing 100 item array over 100,000 iterations:

isset                                   17.678022384644
array_key_exists                        94.587087631226
^E_NOTICE                               66.627979278564
-------------------------------------------------------
Testing 1,000 item array over 100,000 iterations:

isset                                   17.863035202026
array_key_exists                        95.493078231812
^E_NOTICE                               66.738128662109
-------------------------------------------------------
Testing 10,000 item array over 100,000 iterations:

isset                                   17.688035964966
array_key_exists                        95.767021179199
^E_NOTICE                               61.712980270386
-------------------------------------------------------
Testing 50,000 item array over 100,000 iterations:

isset                                   17.810821533203
array_key_exists                        91.847896575928
^E_NOTICE                               61.782121658325
-------------------------------------------------------
Testing 100,000 item array over 100,000 iterations:

isset                                   17.742872238159
array_key_exists                        98.483085632324
^E_NOTICE                               62.968015670776

-------------------------------------------------------
                    average (ms)        total (ms)
-------------------------------------------------------
isset               17.843961715698     107.06377029419
array_key_exists    95.373034477234     572.2382068634
^E_NOTICE           65.155506134033     390.9330368042

noticetest.php

<?php

$iterations = 100000;

$sizes = [10, 100, 1000, 10000, 50000, 100000];

$totals = [
    'isset'    => 0,
    'array_key_exists'  => 0,
    '^E_NOTICE'   => 0,
];


echo "PHP Version ".phpversion()."\n\n";

foreach ($sizes as $size) {
    $source = array_fill(0, $size, true);

    echo str_repeat('-', 55)."\n";

    echo "Testing ".number_format($size)." item array over ".number_format($iterations)." iterations:\n\n";

    error_reporting(E_ALL);

    $start = microtime(true);

    for ($i = 0; $i < $iterations; $i++) {
        if (isset($source['foo'])) {
            $val = $source['foo'];        
        }
    }

    $end = microtime(true);

    $duration = ($end - $start) * 1000;

    $totals['isset'] += $duration;

    echo str_pad('isset', 40)."{$duration}\n";

    //-----------------------------------------------------------------------------

    error_reporting(E_ALL);

    $start = microtime(true);

    for ($i = 0; $i < $iterations; $i++) {
        if (array_key_exists('foo', $source)) {
            $val = $source['foo'];
        }
    }

    $end = microtime(true);

    $duration = ($end - $start) * 1000;

    $totals['array_key_exists'] += $duration;

    echo str_pad('array_key_exists', 40)."{$duration}\n";

    //-----------------------------------------------------------------------------

    error_reporting(E_ALL ^ E_NOTICE);

    $start = microtime(true);

    for ($i = 0; $i < $iterations; $i++) {
        $val = $source['foo'];
    }

    $end = microtime(true);

    $duration = ($end - $start) * 1000;

    $totals['^E_NOTICE'] += $duration;

    echo str_pad('^E_NOTICE', 40)."{$duration}\n";

    //-----------------------------------------------------------------------------
}

echo "\n".str_repeat('-', 55)."\n";
echo str_pad('', 20);
echo str_pad('average (ms)', 20);
echo str_pad('total (ms)', 20)."\n";
echo str_repeat('-', 55)."\n";

foreach ($totals as $name => $total) {
    echo str_pad($name, 20);
    echo str_pad($total/count($sizes), 20);
    echo str_pad($total, 20)."\n";
}

echo "\n";