第一種 function random_number2($length) { $key = ''; $pattern = "123456789ABCDEFGHIJKLMNPQRSTUVWXYZ"; for ($i = 0; $i < $length; $i++) { $key .= $pattern{rand(0, 33)}; } return $key; } 第二種(推薦) uniqid(prefix, more_entropy)是基於微秒計的當前時間而生成一個唯一ID, 預設返回字串有13個字串長,如果more_entropy為true則有23個字串長。 substr(md5(uniqid(rand(),true)),0 , 15) 第三種 class Code { //密碼字典 private $dic = array( 0 => '0', 1 => '1', 2 => '2', 3 => '3', 4 => '4', 5 => '5', 6 => '6', 7 => '7', 8 => '8', 9 => '9', 10 => 'A', 11 => 'B', 12 => 'C', 13 => 'D', 14 => 'E', 15 => 'F', 16 => 'G', 17 => 'H', 18 => 'I', 19 => 'J', 20 => 'K', 21 => 'L', 22 => 'M', 23 => 'N', 24 => 'O', 25 => ...