Trying to search an array that contains special characters:
$array=array("0|0Name"=>"first name","0|1last"=>"last name","1|0email"=>"email address");
tried
  $v="0|0";
  print_r(preg_grep("/^".$v.".*/",$array)); --->FAIL
tried:
  $v=str_replace("|","\|","0|0");
  print_r(preg_grep("/^".$v.".*/",$array)); --->FAIL
 
                        
Use
preg_quote(), it will escape the special characters, taking into account the delimiter (in your case,/):