Is Associative Array or Indexed Array Benchmarks.

IsAssociativeArrayBench.php

<?php

// usage
if(!isset($argv[1])){
    echo "\nUsage: ".$argv[0]."  [options] iterations

    Required: 
        iterations - Number of iterations of each test

    Example:
        php $argv[0] -v 1000
            

    Options:
        -v  
        --verbose
            Show verbose information. Return status for single iteration of each test. 

    ";
    exit(1);
}

// command line options
$options = getopt('v', array('verbose'));
$verbose = isset($options['v']) || isset($options['verbose']);

/**
 * Arrays to check
 */
$tests = array(
    array(array(
        'foo' => 'bar',
    )),
    array(array(
        'bar',
        'foo' => 'bar',
        'baz',
    )),
    array(null),
    array(true),
    array(false),
    array(0),
    array(1),
    array(0.0),
    array(1.0),
    array('string'),
    array(array(0, 1, 2)),
    array(new stdClass),
    array_fill(0,1000,uniqid()),                // big numeric array

    array_fill_keys(range(2,1000,3),uniqid()),  // big misaligned numeric array (=associative)

    array_fill_keys(                            // big associative array
        str_split(
            str_repeat(uniqid('',true),100),
            3
        ),
        true
    )
);

$iterations = (int)$argv[1];

/**
 * Common methods to check associative array
 */
$methods = array(
    'method1 (array_values check)' =>
        function($array){
            return (array_values($array) !== $array);
        },

    'method2 (array_keys comparison)' =>
        function($array){
            $array = array_keys($array); return ($array !== array_keys($array));
        },
    'method3 (array_filter of keys)' =>
        function($array){
            return count(array_filter(array_keys($array), 'is_string')) > 0;
        },

    'method4 (foreach typecast)' =>
        function($array){
            foreach($array as $key => $value) {
                if ($key !== (int) $key) {
                    return true;
                }
            }
            return false;
        },

    'method5 (foreach typecheck)' =>
        function($array){
            foreach($array as $key => $value) {
                if (!is_int($key)) {
                    return true;
                }
            }
            return false;
        },

    'method6 (range array_keys)' =>
        function($array){
            return $array === array() || range(0, count($array)-1) === array_keys($array);
        },

        
);

/**
 * Perform benchmark on each method
 */
foreach($methods as $name=>$func){
    echo "Testing $name - $iterations iterations\n";
    $time = microtime(true);

    // show test results
    if ($verbose) { // verbose
        foreach($tests as $array){
            var_dump($func($array));
        }
    }

    // show test benchmarks
    for($x=0;$x<$iterations;$x++){
        foreach($tests as $array){
            ($func($array));
        }
    }

    /**
     * Show results
     */
    $totalTime = (microtime(true) - $time);
    $avgTime = @($totalTime / ($iterations * count($tests)));

    echo "  Total time: ".number_format($totalTime,5,'.',' ')." s\n";
    echo "  Average   : ".number_format($avgTime*1000,5,'.',' ')." ms / test \n";
    echo "\n";
}

System:

Microsoft Windows [Version 6.1.7601] Intel64 Family 6 Model 58 Stepping 9 GenuineIntel ~2601 Mhz

PHP 5.5.12 (cli) (built: Apr 30 2014 11:20:58)
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2014 Zend Technologies
    with Xdebug v2.2.5, Copyright (c) 2002-2014, by Derick Rethans

Results:

Testing method1 (array_values check) - 1000 iterations
  Total time: 0.39100 s
  Average   : 0.02607 ms / test

Testing method2 (array_keys comparison) - 1000 iterations
  Total time: 0.57720 s
  Average   : 0.03848 ms / test

Testing method3 (array_filter of keys) - 1000 iterations
  Total time: 6.00601 s
  Average   : 0.40040 ms / test

Testing method4 (foreach typecast) - 1000 iterations
  Total time: 0.54600 s
  Average   : 0.03640 ms / test

Testing method5 (foreach typecheck) - 1000 iterations
  Total time: 5.80421 s
  Average   : 0.38695 ms / test

Testing method6 (range array_keys) - 1000 iterations
  Total time: 0.65520 s
  Average   : 0.04368 ms / test