20 Random Alphanumeric Passwords

The passwords:


HduXUn7qFWa4uPnGemf6
T6y4R7aFgyDw7vMDXvmk
gYUbchp4jHYT84TFnWMd
JcM3jUaKnddthJejCSTQ
TW7LkQ97JYrcnRmj6BMX
MozrHT7c4wHWkpRTAczx
ou9J8QmrG4tNfjC9bXbR
zzLyGs4Y7NzVTpow7cSW
RLgkc4S4mpAS98W8fzQf
DupsBbUvbe2dwWXTZTak
wN22XzfJyr2y2C28NRUp
Fuktutsu4mtvRCexSRqU
b38jkvQwtuqyo7tsd8RM
wE79AVKJVTSh9bEBVgcU
LBnsdJZ2qBMnkyLGnTKM
wYd3yNZUfvjvhFQkV9F6
jkRC8DKv7GskPbpKrrFa
bu2YmSNLHdD9orqZkRXb
o38gtvEAPRCZLHwFetQg
9gLHrRyLx2Jbm7sXQFz9

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);