From af201763b6e975fe96d95236d0521b75d8599be2 Mon Sep 17 00:00:00 2001
From: codemasher <smiley@chillerlan.net>
Date: Sun, 5 Apr 2020 03:24:35 +0200
Subject: [PATCH] :shower: clean up QRCode::checkString()

---
 src/QRCode.php | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/QRCode.php b/src/QRCode.php
index 4fc5160ef..f83bcc39e 100755
--- a/src/QRCode.php
+++ b/src/QRCode.php
@@ -20,7 +20,7 @@ use chillerlan\QRCode\Output\{
 };
 use chillerlan\Settings\SettingsContainerInterface;
 
-use function call_user_func_array, class_exists, in_array, mb_internal_encoding, ord, strlen, strtolower;
+use function call_user_func_array, class_exists, in_array, mb_internal_encoding, ord, strlen, strtolower, str_split;
 
 /**
  * Turns a text string into a Model 2 QR Code
@@ -288,10 +288,9 @@ class QRCode{
 	 * checks is a given $string matches the characters of a given $charmap, returns false on the first invalid occurence.
 	 */
 	protected function checkString(string $string, array $charmap):bool{
-		$len = strlen($string);
 
-		for($i = 0; $i < $len; $i++){
-			if(!isset($charmap[$string[$i]])){
+		foreach(str_split($string) as $chr){
+			if(!isset($charmap[$chr])){
 				return false;
 			}
 		}