php - 如何在不使用 rand() 函数的情况下获取固定长度的字符串

Question

如何在不使用rand()函数的情况下获取固定长度的字符串？

我有这个但我不想使用 rand() 函数

function generateRandomString($length =6) {
    $characters = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
    $charactersLength = strlen($characters);
    $randomString = '';

    for ($j = 0; $j < $length; $j++) {
        $randomString .= $characters[mt_rand(0, $charactersLength - 1)];
    }

  return $randomString;
 }

Answer 1

<?php
$start=0;$length=6;
$str='0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
$Val=substr(str_shuffle($str),$start,$length);
echo $Val;
?>