20 Random Alphanumeric Passwords

The passwords:


AGamSQn9PLEus6ezYp9y
qXjEvKcHEHqZHCw4SYKx
CBSek69Vd6MQBnGDDuAb
gecx67hWryDgv7NcHtJk
vz9YdZBH93CuoDqcPsbS
qqCtGL3TMkJPnEjKKGkA
y9BPJqDwfqM28Umqkrkp
mw27hvNuMwdNVeRWHCZy
BPTutWXdW4ads6qJ6ZEx
zkcUTtvQbz3rMqJjPeYm
wSLAH9sS3g3T47xL7sTE
HxZDJuP6Grz6k42esTc2
S3ufZBjuSzN79AyJwA7J
sHuvpEYqADjDCAQ2cdse
qGXTjvSrYbAvpqCQo4P2
CmaFQjHD9rWRrXxMd8Jn
KyuK99u7NPfZA2KPsgNu
3o7PmoFGgVfrEQpsMWmr
T4FP4MNewKycWdfWRAxT
jHhE6pWCDTAymbSLeq8N

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);