Most efficient random string method

[plznty]

currently using

function gen_chars($length = 6) {
    // Available characters
    $chars = '0123456789abcdefghjkmnoprstvwxyz';

    $Code  = '';
    // Generate code
    for ($i = 0; $i < $length; ++$i)
    {
        $Code .= substr($chars, (((int) mt_rand(0,strlen($chars))) - 1),1);
    }
return $Code;
}

// Usage
$var = gen_chars(12);

echo $var;

 

However ide like to know if theres a more efficient way of generating this since this is going to be using a lot.

 

Thanks

[BlueSkyIS]

mt_rand generates an integer. is it helpful to put (int) in front of it?

[plznty]

nah i just need random letters/numerals generated. ty

[mikecampbell]

In my test this was about 15% faster then your original - it eliminates a bunch of calls to strlen.

 

function gen_chars($length = 6) {
    // Available characters
    $chars = '0123456789abcdefghjkmnoprstvwxyz';
    $len = strlen($chars);

    $Code  = '';
    // Generate code
    for ($i = 0; $i < $length; ++$i)
    {
        $Code .= substr($chars, ((mt_rand(0,$len)) - 1),1);
    }
return $Code;
}

 

However, this was about twice as fast (for whatever reason)!

 

function gen_chars($length = 6) {
   // Available characters
   $chars = '0123456789abcdefghjkmnoprstvwxyz';
   $charsarray = str_split($chars);
   $len = strlen($chars)-1;

   $Code  = '';
   // Generate code
   for ($i = 0; $i < $length; ++$i) {
       $Code .= $charsarray[(mt_rand(0,$len))];
   }
}

 

Of course, I tested building a string 500,000 characters long, so if you are only building short strings then yours will be faster! (less overhead)

[plznty]

Thank you!

[sharal]

Or simply:

 

$myvalue = uniqid();
echo $myvalue;

 

http://dk.php.net/manual/en/function.uniqid.php