Hi,
For Processing N dimension array, what type of looping statement is effective

CHeck the below sample code


<?

function microtime_float()
{
list($usec, $sec) = explode(" ", microtime());
return ((float)$usec + (float)$sec);
}

function createRandomString($len = 8) {
$chars = "abcdefghijkmnopqrstuvwxyz023456789";
srand((double)microtime()*1000000);
$i = 0;
$pass = '' ;
while ($i <= $len) {
$num = rand() % 33;
$tmp = substr($chars, $num, 1);
$pass = $pass . $tmp;
$i++;
}
return $pass;
}

$max_element = 1000;

// Initialize array, filling random keys and values
for ($i = 0; $i <= $max_element; $i++) {
$test_array[createRandomString(8)] = createRandomString(64);
}

function ForEachLoop() {
global $test_array;
foreach ($test_array as $ele) {
$tmp[] = $ele;
}
}

function WhileListEachLoop() {
global $test_array;
while (list(, $ele) = each($test_array)) {
$tmp[] = $ele;
}
}

function ForEachLoopWithKey() {
global $test_array;
foreach ($test_array as $k=>$ele) {
$tmp[] = $ele;
}
}

function WhileListEachLoopWithKey() {
global $test_array;
while (list($k, $ele) = each($test_array)) {
$tmp[] = $ele;
}
}

function GetKeyLoop() {
global $test_array;
$keys = array_keys($test_array);
$count = sizeOf($keys);
for ($i=0; $i<$count; $i++) {
$tmp[] = $test_array[$keys[$i]];
}
}

$tests = array(
'ForEachLoop', 'WhileListEachLoop', 'ForEachLoopWithKey', 'WhileListEachLoopWithKey', 'GetKeyLoop'
);

$test_score = array();
foreach ($tests as $test) {
// Foreach test
for ($a=1; $a<=5; $a++) {
reset($test_array);
$timestart = microtime_float();
call_user_func($test);
$time_took = microtime_float() - $timestart;
$test_score[$test][] = $time_took*1000;
}
}

?>
<table cellpadding=4 border=0 cellspacing=2>
<tr>
<th>Loop style</th>
<th>Test 1</th>
<th>Test 2</th>
<th>Test 3</th>
<th>Test 4</th>
<th>Test 5</th>
<th>Average</th>
</tr>
<? foreach ($tests as $test) { ?>
<tr>
<td><?=$test; ?></td>
<? foreach ($test_score[$test] as $score) { ?>
<td align=right><?=number_format($score, 2); ?></td>
<? } ?>
<td align=right><?=number_format(array_sum($test_score[$test])/sizeof($test_score[$test]), 2); ?></td>
</tr>
<? } ?>
</table>

The performance of foreach function is best when compared with other array loop execution functions

Cheers

Senthil Kumar S.