20 Random Alphanumeric Passwords

The passwords:


xBAE9vDtzDUomqCuXPfR
3ZJ4YvZx9kDCZaqKDxfQ
qNAWkREcHrHTAZMtgNXf
t8eezBHezkrShqNmayoo
sozhZwJzafnMHkV6DzYW
2a7GfQ3WfSojy92CN7CL
nsvVmPeLQGyUxKHcCRwJ
9nJnmD6qNZpcQGdbrXpG
aaWqPw2aCSe4ux2aj3mM
MDdwHnmaJpgd9SSExRV8
Ub8LaDQaHurofGWT989p
DF9RKCPbbSVxzbQLPM98
VdCSaRyQL6nsgG6dUrWs
aSGHsnpwJTbZMATzMbeg
JnShmEF6ZrznHFDNBQqT
swJT6Hf2Zqqmaa6SRS4H
z3xXFjjSAy2yWTVZzvyS
8TKsKJCZ4BUjwpJV7A9q
4yKX2pYKBSAnxs4BrCdE
mJGWb6RjGrqkAAmZxyrE

The code for the class

<?php

/**
 * Class PasswordGenerator
 */
class PasswordGenerator
{

    public static $letters = "2346789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghjkmnopqrstuvwxyz";
    public static $length = "20";
    public $letters_array;

    function __construct()
    {
        $this->letters_array = array();

        for ($a = 0; $a < strlen(self::$letters); $a++) {
            $this->letters_array[] = self::$letters[$a];
        }
    }


    function make(): string
    {
        $password = '';
        for ($i = 0; $i < self::$length; $i++) {
            srand((float)microtime() * 10000000);
            $password .= $this->letters_array[array_rand($this->letters_array)];
        }
        return $password;

    }

    function printOne()
    {
        print $this->make();
    }

    function printMany($num)
    {
        for ($i = 0; $i < $num; $i++) {
            $this->printOne();
            print "\n";
        }
    }


}

How to invoke the class

$PG = new PasswordGenerator();
$PG->printMany(20);