Check if String Is Equal to Items in Array

This function will test if any of the strings in an array is equal to a given string. You can specify case sensitivity.

// tests if $needle is equal to any strings in $haystack
function str_equal_array($needle, $haystack, $case_insensitive = TRUE) {
	if (!is_string($needle) || !is_array($haystack)) {
		return FALSE;
	}
	if ($case_insensitive) {
		$needle = strtolower($needle);
	}
	foreach ($haystack as $hay) {
		if (!is_string($hay)) {
			continue;
		}
		if ($case_insensitive) {
			$hay = strtolower($hay);
		}
		if ($needle == $hay) {
			return TRUE;
		}
	}
	return FALSE;
}