View difference between Paste ID: 8dscpkkY and R1j43YBE

-  public  function addCharsAt(int $index,string $char){
+<?php
 class Foo {
-        $is_added=FALSE;
+    public $string = '';
-        for ($i=0;$i<$this->length;$i++) {
+    //public $length = 0;
-            if (!$is_added&&$i == $index) {
+
-                $str .= $char;
+    public function __get (string $name) {
-                $is_added=TRUE;
+        if($name === 'length') return strlen($this->string);
-                $i--;//go back one step.
+        $trace = debug_backtrace();
-            }
+        trigger_error(
-            else
+            'Undefined property via __get(): ' . $name .
-               $str.=$this->string[$i];
+            ' in ' . $trace[0]['file'] .
             ' on line ' . $trace[0]['line'],
-        $this->string=&$str;
+            E_USER_NOTICE);
-        $this->length++;
+        return null;
-    }
+    }
 
     public function __isset ( string $name ) : bool {
         if($name === 'length') return true;
         return false;
     }
 
     public function __debugInfo() : array {
         return [
             'length' => $this->length,
             'string' => $this->string
         ];
     }
 
 
 
     public function addCharsAt(int $index, string $chars) {
         if(strlen($chars) === 0 || $index < 0 || $index > 1 + $this->length) return null;
         $str='';
         $len = $this->length;
         for ($i = 0; $i <= $len;) {
             if ($i === $index) {
                 $str .= $chars;
                 $index = -1;
                 //$this->length += strlen($chars);
             } elseif ($i < $len) {
                $str .= $this->string[$i];
                $i++;
             } else break;
         }
         $this->string=$str;
         return null;
     }
 
 
 }
 
 
 $foo = new Foo();
 
 
 $foo->addCharsAt(0, "test");
 var_dump($foo);
 
 $foo->addCharsAt(2, "xx");
 var_dump($foo);
 
 $foo->addCharsAt(6, "yy");
 var_dump($foo);