How do i rand string according to index size

Question

I don't really know how to go about but it really pretty for me in achievement like each rand_string to each index.

My code:

function rand_string($length) {
  $str="";
  $chars = "abcdefghijklmanopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  $size = strlen($chars);
  for($i = 0; $i < $length; $i++) {
    $str .= $chars[rand(0, $size-1)];
  }
  return $str;
}

$pcode = rand_string(4);
for ($b = 0; $b < 3; $b++) {
  echo $pcode[$b];
}

I am expecting something like: 9cwm cZnu c9e4 in the output. Can I achieve this in PHP?

Currently, with my code, I get a string from rand_string in each index like 9cw.

Could you just redact your post(title included) so we could get your intentions more clear? Right now I could only guess that you wanna print 3 random strings... so you should instead of what you are doing now just echo rand_string(4) inside of that second loop. — Arek Bal, Nov 23 '17 at 23:26
Possible duplicate of [PHP: How to generate a random, unique, alphanumeric string?](https://stackoverflow.com/questions/1846202/php-how-to-generate-a-random-unique-alphanumeric-string) — mickmackusa, Nov 24 '17 at 01:32

YouneL · Accepted Answer · 2017-11-23T23:53:26.663

1

Your code works, you only need to call rand_string inside your second loop in order to get something like 9cwm cZnu c9e4 (what you have described in your question).

Here is a working example:

function rand_string($length) {
    $str="";
    $chars = "abcdefghijklmanopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
    $size = strlen($chars);
    for($i = 0;$i < $length;$i++) {
        $str .= $chars[rand(0,$size-1)];
    }
    return $str;
}

// call rand_string inside for loop
for ($b = 0; $b<3; $b++) {
    echo rand_string(4).' ';
}

Try it online

edited Nov 23 '17 at 23:53

answered Nov 23 '17 at 23:47

YouneL

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in more tips can i get back these string in one line? Example: `string(12) "9cwmcZnuc9e4"` – Kingsley Plaza Nov 24 '17 at 01:00
Yes Of course, just do `echo rand_string(4);` without concatinating ' ' in the last loop – YouneL Nov 24 '17 at 01:02
Geting this string back in one line is in hard size dont seem to be working as expect do a checkup – Kingsley Plaza Nov 24 '17 at 10:12
Do you want to be like this: [Demo](http://sandbox.onlinephpfunctions.com/code/5f6430e7bee33ac7af27bd7add08c245fa629b80) ? – YouneL Nov 24 '17 at 10:30
Yes but in one var_dump string line example: function rand_string($length) { $str=""; $chars = "abcdefghijklmanopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; $size = strlen($chars); for($i = 0;$i < $length;$i++) { $str .= $chars[rand(0,$size-1)]; } return $str; } // call rand_string inside for loop for ($b = 0; $b<3; $b++) { $onestringline = rand_string(4); var_dump($onestringline); } expecting string( 12) "jd9mjjmdagja" – Kingsley Plaza Nov 24 '17 at 10:51
You have to use a variable to collect random string and then use var_dump to show it: [Example](http://sandbox.onlinephpfunctions.com/code/4014418920358f72ba802ebfbdb82bdeff05e0e6) – YouneL Nov 24 '17 at 10:58
Yes very wish never thought big thanks for long time coparation – Kingsley Plaza Nov 24 '17 at 11:16

score 0 · Answer 2 · answered Nov 23 '17 at 23:50

The generation of the string actually works in your code. You aren't calling/printing the function correctly. Just call the function three times and print all the results (with spaces in between). Instead of printing you could join it together in a string and remove the last space.

<?php
function rand_string($length) {
  $str="";
  $chars = "abcdefghijklmanopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  $size = strlen($chars);
  for($i = 0;$i < $length;$i++) {
   $str .= $chars[rand(0,$size-1)];
  }
  return $str;
 }

  for ($b = 0; $b<3; $b++)
   {
    echo rand_string(4)." ";
    }

hexYeah · Answer 3 · 2017-11-24T00:02:31.853

-1

If you don't mind using a completely different approach, limited to 32 chars :

return substr(md5(mt_rand().time()), 0, $length);

It's not super random but you get the picture...

Thanks to CM and user2693053 for bringing stuff to my attention (updated answer)

using mt_rand() instead of rand()
md5() length of 32...

edited Nov 24 '17 at 00:02

answered Nov 23 '17 at 23:20

hexYeah

1,040
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i can't detect your method please edit with more codes or idea thanks – Kingsley Plaza Nov 23 '17 at 23:32
The idea is that you use `md5(rand().time()` to generate a reasonably random string by hashing a combination of a random number and the current time. After that `substr()` is used to return a part of that string with length `$length`. Keep in mind that `md5()` returns a string of 32 characters, so work around that if you can have `$length > 32`. – Niellles Nov 23 '17 at 23:38
`rand()` is not recommended and is an alias for `mt_rand()` in PHP 7. For backwards compatibility reasons you should use `mt_rand()` instead. Hope I helped! -CM – Cole Nov 23 '17 at 23:42
Thank you guys for your comments ! I will update my answer and credit you ;) – hexYeah Nov 23 '17 at 23:56

How do i rand string according to index size

3 Answers3