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php random number principle:
##The system automatically generates a random number seed (mt_srand The function can generate seeds by itself), mt_rand first determines whether there is a generated seed, if not, it automatically generates one, and then generates a random number based on the seed.
Generate 10000-99999 random numbers: (Recommended learning:PHP programming from entry to proficiency)
mt_rand(10000,99999); //php提供的随机数为伪随机数(计算机只能生成伪随机数,php英文文档上有警告此随机数不要使用于token生成的操作) //伪随机是由可确定的函数（常用线性同余），通过一个种子（常用时钟），产生的伪随机数。A small experiment:
mt_srand(10); //播种随机数种子 echo mt_rand(1,100).PHP_EOL; //生成随机数 echo mt_rand(1,100).PHP_EOL; //生成随机数 //然后你会发现无论你怎么刷新网页，生成的随机数都是一样的!! //建议使用openssl_random_pseudo_bytes生成tokenExplode the random number seed and use the tool php_mt_srand to generate a random string number:
$chars = 'abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'; $chars .= '`~!@#$%^&*()_+-=[]{};:"|,.<>/?'; $str=substr(str_shuffle($chars),0,10); //10位随机数 //中英文混合随机可以会出现乱码因为str_shuffle是基于字符随机打乱 //不能直接使用str_split函数，因为该函数也是基于字符串的 //PS:疯狂吐槽中文 function mb_str_split($str){ //切割中文字符串 return preg_split('/(?
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