Test to see which is quicker, explode or substring to find the last part of a php class name

speed.php

<?php

// How many times to we want to iterate
$count = isset($argv[1]) ? $argv[1] : 1000;

// Which function are we wanting to test
if (isset($argv[2]) && in_array($argv[2], array('explodeVersion', 'substringVersion'))) {
    $function = $argv[2];
} else {
    $function = 'explodeVersion';
}

// main
echo 'Functions to test:'.PHP_EOL;
echo ' - explodeVersion'.PHP_EOL.' - substringVersion'.PHP_EOL.PHP_EOL;
echo 'Started: '.date('d-m-Y H:i:s').PHP_EOL;
echo 'Running with function: '.$function.PHP_EOL;
$timerStart = microtime(true);
iterate($count, $function);
$timerEnd = microtime(true);
$overall = $timerEnd - $timerStart;
echo 'Time taken: '.sprintf('%0.6f', $overall).PHP_EOL;
echo 'Peak Memory Usage: '.memory_get_peak_usage().PHP_EOL;
echo 'Completed: '.date('d-m-Y H:i:s').PHP_EOL;


/**
 * Iterate for data generation
 *
 * @param int    $count    How many times we want to iterate
 * @param string $function Which function we want to run
 *
 * @return string
 */
function iterate($count, $function) {

    $class = 'DocBlox_Parser_DocBlock_Validator_File';   
    for ($i = 0; $i <= $count; $i++) {
        $part = $function($class);
        echo "Iterating: $i\r";
    }    
    echo PHP_EOL;
}

/**
 * Explode Version
 *
 * @param string $string The class name
 *
 * @return string
 */
function explodeVersion($string)
{
    $parts = explode('_', $string);
    return $parts[count($parts) - 1];
}

/**
 * Substring Version
 *
 * @param string $string The class name
 *
 * @return string
 */
function substringVersion($string)
{
    return substr($string, strrpos($string, '_') + 1);    
}