生成随机 5 个字符的字符串
我想创建精确的 5 个随机字符串,并且复制的可能性最小.最好的方法是什么?谢谢.
I want to create exact 5 random characters string with least possibility of getting duplicated. What would be the best way to do it? Thanks.
推荐答案
$rand = substr(md5(microtime()),rand(0,26),5);
这可能是我最好的猜测——除非您也在寻找特殊字符:
Would be my best guess--Unless you're looking for special characters, too:
$seed = str_split('abcdefghijklmnopqrstuvwxyz'
.'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
.'0123456789!@#$%^&*()'); // and any other characters
shuffle($seed); // probably optional since array_is randomized; this may be redundant
$rand = '';
foreach (array_rand($seed, 5) as $k) $rand .= $seed[$k];
示例
而且,对于基于时钟的一个(因为它是增量的,所以冲突更少):
And, for one based on the clock (fewer collisions since it's incremental):
function incrementalHash($len = 5){
$charset = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
$base = strlen($charset);
$result = '';
$now = explode(' ', microtime())[1];
while ($now >= $base){
$i = $now % $base;
$result = $charset[$i] . $result;
$now /= $base;
}
return substr($result, -5);
}
注意:增量意味着更容易猜测;如果您将其用作盐或验证令牌,请不要使用.WCWyb"的盐(现在)意味着 5 秒后它是WCWyg")
相关文章