Description:
------------
---
From manual page: http://www.php.net/function.in-array
---
<?php
clearstatcache();
$time_start = microtime(true);
// generate an array
$arr = array();
for($i=0; $i<100000; $i++) {
	$key = rand(0, 100000000);
	$val = rand(0, 100000000);
	$arr["{$key}"] = "{$val}";  
}
$time_end = microtime(true);
$time = $time_end - $time_start; //round(, 6);

echo "Time for cretion of array: {$time} seconds";
clearstatcache();

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

$time_start = microtime(true);
// Record time
// search using foreach function
foreach ($arr as $key=>$val) {
	if($val === "1000") {
		echo "<br />Found";
	}
}

// Display time
$time_end = microtime(true);
$time = $time_end - $time_start; //round($time_end - $time_start, 4);
echo "<br />Time for FOREACH of array: {$time} seconds";

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

$time_start = microtime(true);
// Record time
// search using in_array function
in_array("1000", $arr);
// Display time
$time_end = microtime(true);
$time = $time_end - $time_start; //round($time_end - $time_start, 4);

echo "<br />Time for in_array() of array: {$time} seconds";
clearstatcache();

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

$time_start = microtime(true);
// Record time
// search using in_array function
array_search("1000", $arr);
// Display time
$time_end = microtime(true);
$time = $time_end - $time_start; //round($time_end - $time_start, 4);

echo "<br />Time for array_search() of array: {$time} seconds";
clearstatcache();

phpinfo();
?>

Output:
Time for cretion of array: 0.2615659236908 seconds
Time for FOREACH of array: 0.013147115707397 seconds
Time for in_array() of array: 0.021516084671021 seconds
Time for array_search() of array: 0.021377086639404 seconds

Problem:
Indigenous functions are supposed to be much faster than foreach or any external 
loop (this is what I read in the book Zend PHP 5 Certification Study Guide), but 
its twice slower here,