How to use the bitwise operator & ?

Hi!

I found a password generator on Interner and it looks like this (my question is in the code):

[code]<?php
// I would like to use lower cased, upper cased and digits, but I cannot set
// the bits, or at least it doesn´t work. What´s wrong?
echo generatePassword(9, 1&2&4);

function generatePassword($length=9, $strength=0) {
$vowels = ‘aeuy’;
$consonants = ‘bdghjmnpqrstvz’;
if ($strength & 1) {
$consonants .= ‘BDGHJLMNPQRSTVWXZ’;
}
if ($strength & 2) {
$vowels .= “AEUY”;
}
if ($strength & 4) {
$consonants .= ‘23456789’;
}
if ($strength & 8) {
$consonants .= ‘@#$%’;
}

$password = ”;
$alt = time() % 2;
for ($i = 0; $i < $length; $i++) {
if ($alt == 1) {
$password .= $consonants[(rand() % strlen($consonants))];
$alt = 0;
} else {
$password .= $vowels[(rand() % strlen($vowels))];
$alt = 1;
}
}
return $password .” “.($strength & 1&2&4);
}

?>[/code]

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