Question

Possible Duplicate:
Compare multiple values in PHP

Will someone help me to find a better way of writing this, please. I feel as if there has to be something better than nested ifs. I have tried searching, but I don’t know what I am looking for.

The code says that if the session variable “auth” is not exactly equal to 0, 1, 2, or 3 then redirect to the login page.

if($_SESSION['auth']!=0){
   if($_SESSION['auth']!=1){
      if($_SESSION['auth']!=2){
         if($_SESSION['auth']!=3){
            header("location:login.php");
         }
      }
   }
}

My initial thought was to do something like this.

if($_SESSION['auth']<=0 || $_SESSION['auth']>=3){
   header("location:login.php");
}

But that doesn’t account for fractions of the integer value. Which I only want to allow integer values. My next thought was this.

if($_SESSION['auth']!=0 && $_SESSION['auth']!=1 && $_SESSION['auth']!=2 && $_SESSION['auth']!=3){
   header("location:login.php")
}

But this way is not much different than all the nested ifs. Let me know if I am just attempting to fix something that isn’t broken. Thank you in advance. A link to the relevant topic (PHP manual preferably) is all I’m looking for, not the solution.

Answer 1

Yes, you are. A simpler approach could be inarray().

$values = array('0','1','2','3');
if(!in_array($_SESSION['auth'], $values, true)
//do something

or even shorter

if(!in_array($_SESSION['auth'], array('0','1','2','3'), true)
//do something

It is probably best to go with the first option, just in case you may want to compare it against more values in the future.