Undefined offset in microtime?

[tPet]

Please forgive my newbie question, and I did search here first .. maybe my old eyes missed an an earlier post with the same issue. So please forgive that too (if applicable) ... But anyway ...

 

I use a random banner generator script on my websites. It works just fine. However, checking my error log I have a slew of these …

 

PHP Notice:  Undefined offset:  1 in [page path] on line 70

 

The function in that area of the script is …

 

function GetBanner($min, $max){

        $mtime = ((double)microtime()* 100000);

        $mtime = explode(" ",$mtime);

        $mtime = doubleval($mtime[1]) + doubleval($mtime[0]);  < -- THIS IS LINE 70

        mt_srand($mtime);

        $randval = mt_rand($min, $max);

        return ($randval) ;

}

 

 

Like I said, the script works peachy, but I hate the idea of it clogging up my error log. Any idea on how I can clean this up?

 

Thanks.

[cags]

Undefined offset means that you have attempted to access an index in an array that doesn't exist, so in your case it is probably $mtime[1]. When you do this it will automatically use an 'empty' value ie '' but will throw a notice level error. I'm not entirely sure of the objective of your code so it's difficult to say how to prevent it. Something like this would probably work...

 

$mtime = doubleval($mtime[0]);
$mtime += (isset($mtime[1])) ? $mtime[1] : 0;

 

But I feel sure the code you are using is overcomplicating the task somewhat.

 

[tPet]

You are a frakin' genius .. Thanks that did it.

 

You are probably correct, the overall code could probably use some cleaning up, but I've been using it for years, and it works great. I just got it into me about finally asking about the sitelog error this morning.

 

Thanks so much again.

[salathe]

Which version of PHP are you using? If it is PHP 4.2.0 or newer (which I really hope it is!!) then most of your function could be removed. It can just be:

 

function GetBanner($min, $max) {
    return mt_rand($min, $max);
}

 

 

Now for why you were getting the notice in the first place.  Stepping through your code piece-by-piece:

 

$mtime = ((double)microtime()* 100000);
$mtime = explode(" ",$mtime);
$mtime = doubleval($mtime[1]) + doubleval($mtime[0]);

• microtime() returns a string like "0.123456 1234567890"
  
• (double) converts that to a floating point number, so the above string would become 0.123456
  
• Multiplied by 100,000 that becomes 12345.6
  
• So $mtime is given the value 12345.6
  
• Next we explode 12345.6 by spaces. There are none so we get an array containing one item: array("12345.6")
  
• So now you can see there is no second array value (at offset 1) for the next line to use!
  

 

P.S. Welcome to PHPFreaks

P.P.S. Hmpf typo... d'oh

[tPet]

Sweet!!!  Thanks,  salathe!