Walks on the values ​​of an array value each time the function is invoked

cycle.php

function cycle($obj)
{
	static $key = -1;
	static $last_obj = array();

	if(count(array_diff_assoc($obj, $last_obj)) > 0)
		$key = 0;
	else
		$key++;

	if(!array_key_exists($key, $obj)) $key = 0;

	$last_obj = $obj;
	
	return $obj[$key];
}

$array1 = array('blue', 'green', '#000', 'red');

for($i = 1; $i <= 5; $i++) {
    echo "<div style='background-color: ".cycle($array1)."'>" . mt_rand() . "</div>\n";
}

$array1 = array('yellow', 'green', 'white', 'red');

for ($i = 1; $i <= 5; $i++) {
    echo "<div style='background-color: ".cycle($array1)."'>" . mt_rand() . "</div>\n";
}