使用现有代码在PHP中生成随机数 - Generating random numbers in PHP with existing code

我使用以下代码，得到6个随机字符。如何将字符数增加到10（或任何其他数字）？这段代码中的什么使它成为6个字符？

function createRandomID() {
$chars = "abcdefghijkmnopqrstuvwxyz0123456789?";
$i = 0;
$pass = "";
while ($i <= 5) {
$num = rand() % 33;
$tmp = substr($chars, $num, 1);
$pass = $pass . $tmp;
$i++;
}
return $pass;
}

您已经得到了正确的答案，因此您的代码变成：

function createRandomID() {
$chars = "abcdefghijkmnopqrstuvwxyz0123456789?";
$i = 0;
$pass = "";
$upTo = 9 // if you want 10 or whatever - 1
while ($i <= $upTo) {
$num = rand() % 33;
$tmp = substr($chars, $num, 1);
$pass = $pass . $tmp;
$i++;
}
return $pass;
}