Solved

Unique number

Posted on 2011-02-22
5
343 Views
Last Modified: 2012-05-11
How I get in php unique 5 character number sequence  example 12093, 48923, 83492 and so on... Everytime when user come in to the page there is unigue five  number sequence?
0
Comment
Question by:mattimeikalainen
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
5 Comments
 

Expert Comment

by:Jason_Lotito
ID: 34952642
Depends on what you mean by unique.  If you mean each time a page shows up, you want a random number that can't be guessed, you can use:

<?php
mt_srand(time());
$random = mt_rand(10000,99999);
echo $random;

Open in new window


At the same time, if you want make that number unique to the user, you'd need to insert the number into a database and then store a reference to that number with the user.  However, if you do that, you limit yourself and the number of numbers.  Should numbers expire?  In this case, could you explain a bit more what you are trying to do?
0
 
LVL 34

Accepted Solution

by:
Beverley Portlock earned 250 total points
ID: 34952964
@Jason - mt_rand doesn't require seeding

@ O/P - the problem with a 5 digit number is that they are not very random since there are only 90,000 of them. A 5 character string has a lot more choice and it is not that hard to build a small function to do what you want

     // Generate a near unique, non-sequential code
     //
     // Parameters: $codeSize - The size of the code to generate. Longer is more secure
     //             $codeChars - The set of characters to use to generate the key
     //
     // Returns: A simple string
     //
     function nearUniqueCode( $codeSize = 5, $codeChars= "" ) {
          $code  = "";
          $chars = ($codeChars != "" ) ? $codeChars : "ABCDEFGHJKLMNPQRTUVWXYZ0123456789";
          $chLen = strlen( $chars );


          // Build the code
          //
          for ( $i=0; $i < $codeSize; $i++ ) {
               $pos =  mt_rand(0, $chLen-1);
               $code .= substr( $chars, $pos, 1 );
          }

          return $code;
     }

Open in new window

0
 

Author Comment

by:mattimeikalainen
ID: 34953261
How I put that bportlock solutions on my page? echo something?
0
 

Author Comment

by:mattimeikalainen
ID: 34953314
That number series goes in forms hidden field <input type="hidden" name="number" value="<?php echo something">
0
 
LVL 34

Expert Comment

by:Beverley Portlock
ID: 34953626
Assuming you have included the function code I posted above, then it could be used lke so

<input type="hidden" name="number" value="<?php echo nearUniqueCode(); >"  />
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
if statement malfunction 5 44
How do I correctly structure this insert statement 3 32
Joomla Editing 3 24
Phone number mask 4 16
This article discusses how to create an extensible mechanism for linked drop downs.
3 proven steps to speed up Magento powered sites. The article focus is on optimizing time to first byte (TTFB), full page caching and configuring server for optimal performance.
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions. Consider email address RFCs: Look at HTML5 form input element (with type=email) regex pattern: T…
This tutorial will teach you the core code needed to finalize the addition of a watermark to your image. The viewer will use a small PHP class to learn and create a watermark.

752 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question