title: Is it necessary to declare null variables manually in php?
body: <p>I am aware that PHP considers undefined variables as null. But despite this, when i want to use one undefined variable it throws an E_NOTICE error saying the variable is undefined. To prevent this, should I fix this E_NOTICE setting variables manually to null?</p>
  
  <p>For example: </p>
  
  <pre><code>class Myclass{
  
   private $var1;
   private $var2;
  
   public function __construct($settings){
    $allowedKeys = array("var1","var2");
    foreach($allowedKeys as $key =&gt; $value){
     if(!isset($settings[$value])){
     $settings[$value] = null;
     }
   }
  
   $this-&gt;var1 = $settings['var1'];
   $this-&gt;var2 = $settings['var2'];
  
   }
  }
  </code></pre>