str_shuffle()
(PHP 4 >= 4.3.0, PHP 5, PHP 7)
随机打乱一个字符串
说明
str_shuffle(string $str) : string
str_shuffle()函数打乱一个字符串,使用任何一种可能的排序方案。
Caution本函数并不会生成安全加密的值,不应用于加密用途。若需要安全加密的值,考虑使用openssl_random_pseudo_bytes()。
参数
- $str
输入字符串。
返回值
返回打乱后的字符串。
更新日志
版本 | 说明 |
---|---|
7.1.0 | 内置的随机算法从 libc rand 函数改成了»梅森旋转演伪随机数发生算法。 |
范例
Example #1str_shuffle()范例
<?php $str = 'abcdef'; $shuffled = str_shuffle($str); // 输出类似于: bfdaec echo $shuffled; ?>
参见
Aoccdrnig to rseearch at an Elingsh uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is that the frist and lsat ltteer is at the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae we do not raed ervey lteter by it slef but the wrod as a wlohe. Hree's a cdoe taht slerbmcas txet in tihs way: <?php function scramble_word($word) { if (strlen($word) < 2) return $word; else return $word{0} . str_shuffle(substr($word, 1, -1)) . $word{strlen($word) - 1}; } echo preg_replace('/(\w+)/e', 'scramble_word("\1")', 'A quick brown fox jumped over the lazy dog.'); ?> It may be ufseul if you wnat to cetare an aessblicce CTCPAHA.
This function is affected by srand(): <?php srand(12345); echo str_shuffle('Randomize me') . '<br/>'; // "demmiezr aon" echo str_shuffle('Randomize me') . '<br/>'; // "izadmeo rmen" srand(12345); echo str_shuffle('Randomize me') . '<br/>'; // "demmiezr aon" again ?>
A proper unicode string shuffle; <?php function str_shuffle_unicode($str) { $tmp = preg_split("//u", $str, -1, PREG_SPLIT_NO_EMPTY); shuffle($tmp); return join("", $tmp); } ?> $str = "Şeker yârim"; // My sweet love echo str_shuffle($str); // ieymrŢekr echo str_shuffle_unicode($str); // Şr mreyeikâ
This page is missing a very important notice: Caution This function does not generate cryptographically secure values, and should not be used for cryptographic purposes. If you need a cryptographically secure value, consider using random_int(), random_bytes(), or openssl_random_pseudo_bytes() instead.
Shuffle for all encoding formats <?php function unicode_shuffle($string, $chars, $format = 'UTF-8') { for($i=0; $i<$chars; $i++) $rands[$i] = rand(0, mb_strlen($string, $format)); $s = NULL; foreach($rands as $r) $s.= mb_substr($string, $r, 1, $format); return $s; } ?>
/** * Test shuffleString */ function testShuffleString() { $shuffled = shuffleString("ĄęźćÓ"); if (\mb_strlen($shuffled) != 5) { throw new \UnexpectedValueException("Invalid count of characters"); } if ($shuffled == "ĄęźćÓ") { throw new \UnexpectedValueException("The same string"); } foreach (["Ą", "ę", "ź", "ć", "Ó"] as $char) { if (\mb_strpos($shuffled, $char) === false) { throw new \UnexpectedValueException("Character not found"); } } } /** * Shuffle string * * @param $stringValue String to shuffle * @param string $startWith Shuffle $stringValue and append to $startWith * @return string Shuffled string * @author Krzysztof Piasecki<krzysiekpiasecki@gmail.com> */ function shuffleString($stringValue, $startWith = "") { $range = \range(0, \mb_strlen($stringValue)); shuffle($range); foreach($range as $index) { $startWith .= \mb_substr($stringValue, $index, 1); } return $startWith; }; testShuffleString(); echo shuffleString("Hello"); // > 'elHol' (something like this) echo shuffleString("World!", "Hello "); // > 'Hello do!lrW' (something like this)
As noted in this documentation str_shuffle is NOT cryptographically secure, however I have seen many code examples online of people using nothing more than this to generate say random passwords. So I though I'd share my function which while it makes use of str_shuffle also rely's on random_int() for added security. I use this function to generate salts to use when working with hashes but it can also be used to generate default passwords for new users for example. It starts with a universe of possible characters, in this case all letters (upper and lower case), 0-9, and several special characters. It then will run str_shuffle on the universe of characters a random number of times, using random_int() (currently set to 1-10) Then once the universe of possible characters has been shuffled it using random_int() once more to select the character as a random position within the shuffled string, as does that once for each character you want in the output. function secret_gen( $len=64 ) { $secret = ""; $charset = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*()_-+=`~,<>.[]: | '; for ( $x = 1l $x <= random_int( 1, 10 ), $x++ ){ $charset = str_shuffle( $charset ); } for ( $s = 1; $s <= $len; $s++ ) { $secret .= substr( $charset, random_int( 0, 86 ), 1 ); } return $secret; }
str_shuffle isn't recommendable for passwords. Each character exists only one time). A function like the following one is better for this. <?php function generatePassword($length = 8) { $possibleChars = "abcdefghijklmnopqrstuvwxyz"; $password = ''; for($i = 0; $i < $length; $i++) { $rand = rand(0, strlen($possibleChars) - 1); $password .= substr($possibleChars, $rand, 1); } return $password; } ?>
To cobine functionality and simplicity of the two functions below we can have: <?php function generatePasswd($numAlpha=6,$numNonAlpha=2) { $listAlpha = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'; $listNonAlpha = ',;:!?.$/*-+&@_+;./*&?$-!,'; return str_shuffle( substr(str_shuffle($listAlpha),0,$numAlpha) . substr(str_shuffle($listNonAlpha),0,$numNonAlpha) ); } ?>
Very, very simple random password generator, without using rand() function: <?php function random_password($chars = 8) { $letters = 'abcefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890'; return substr(str_shuffle($letters), 0, $chars); } ?>
Shortend function for PHP < 4.3 <?php function RandomPass($numchar) { $word = "a,b,c,d,e,f,g,h,i,j,k,l,m,1,2,3,4,5,6,7,8,9,0"; $array=explode(",",$word); shuffle($array); $newstring = implode($array,""); return substr($newstring, 0, $numchar); } ?>