Generate random between alphanumeric min and max in PHP - php

Question

I am looking for an approach like mt_rand to generate a random value, but between two alphanumeric values instead of integers.
For example, rand(g3j3j4k5, z9kDDkks8f8d).
I tried to convert the alphanumeric values to integers by base_convert. Beside the fact, it is somehow overkill, sometimes the integer is more than 15 digits, and thus not working in PHP rand functions.
NOTE: It is not about making a random string with given length. The value should between two given values, exactly like a random number between min and max integers.

Answer 1

This should work for you:
Here I split $min and $max into an array with str_split() and loop through each character of both arrays with array_map().
There I get the position of the character with strpos() and return a random alphanum character in that particular range. If min is bigger than max I just return a random character from the entire range.
Code:
<?php
function alphanum_rand($min = "", $max = ""){
$chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
$random = array_map(function($minC, $maxC)use($chars){
if(($minKey = strpos($chars, $minC)) < ($maxKey = strpos($chars, $maxC)))
return $chars[mt_rand($minKey, $maxKey)];
else
return $chars[mt_rand(0, strlen($chars))];
}, str_split($min), str_split($max));
return implode("", $random);
}
echo alphanum_rand("g3j3j4k5", "z9kDDkks8f8d");
?>

Answer 2

You could try a simple PHP Function and define a random string alpha numeric and can also include special characters. For loop will do the magic for u :)
function RandomString($size)
{
$chars = "abcdefghijklmnopqrstuwxyzABCDEFGHIJKLMNOPQRSTUWXYZ0123456789";
$string = array();
$alphaLength = strlen($chars) - 1;
for ($i = 0; $i < $size; $i++) {
$n = rand(0, $alphaLength);
$string[] = $chars[$n];
}
return implode($string);
}
and simple call it with the size you need.
<?php
echo RandomString(5); // Length of strings
?>