Is it necessary to declare null variables manually in php? -

i aware php considers undefined variables null. despite this, when want use 1 undefined variable throws e_notice error saying variable undefined. prevent this, should fix e_notice setting variables manually null?

for example:

class myclass{   private $var1;  private $var2;   public function __construct($settings){   $allowedkeys = array("var1","var2");   foreach($allowedkeys $key => $value){    if(!isset($settings[$value])){    $settings[$value] = null;    }  }   $this->var1 = $settings['var1'];  $this->var2 = $settings['var2'];   } } 

you have 4 options prevent e_notice:

one set variable either null, string, integer before use variable. i.e.:

$variable = null; $variable = ''; $variable = 0; $variable = [];  ...  if(empty($variable)) {     // situation } 

the other check if variable exists. did in 1 line:

if(isset($variable)){    ... } 

third 1 turn off e_notice in scipt:

error_reporting(e_all & ~e_notice); 

forth 1 turn off in php.ini file (though not recommend this):

error_reporting = e_all & ~e_notice // must find line in php.ini