str_shuffle
(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)
str_shuffle — 文字列をランダムにシャッフルする
説明
str_shuffle() は文字列をシャッフルします。 考えられるすべての順列のうちのひとつを作成します。
警告
この関数が生成する値は、暗号学的にセキュアではありません。そのため、これを暗号や、戻り値を推測できないことが必須の値として使っては いけません。
暗号学的にセキュアな乱数が必要な場合は、Random\Randomizer を Random\Engine\Secure と一緒に使いましょう。簡単なユースケースの場合、random_int() と random_bytes() 関数が、オペレーティングシステムの CSPRNG を使った、 便利で安全な API を提供します。
パラメータ
string-
入力文字列。
戻り値
シャッフルされた文字列を返します。
例
例1 str_shuffle() の例
<?php
$str = 'abcdef';
$shuffled = str_shuffle($str);
// bfdaec のような文字列を返します
echo $shuffled;
?>参考
- Random\Randomizer::shuffleBytes() - 指定された文字列の、バイト単位の順列を取得する
- Random\Randomizer::shuffleArray() - 配列の順列を取得する
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User Contributed Notes 13 notes
jojersztajner at OXYGEN dot POLAND ¶
17 years ago
Aoccdrnig to rseearch at an Elingsh uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is that the frist and lsat ltteer is at the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae we do not raed ervey lteter by it slef but the wrod as a wlohe.
Hree's a cdoe taht slerbmcas txet in tihs way:
<?php
function scramble_word($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.
ronald ¶
9 years ago
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.
blamoo2 at hotmail dot com ¶
9 years ago
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
?>
ccb2357 at gmail dot com ¶
1 year ago
<?php
function str_rand(int $length = 20) : string {
$ascii_codes = range(48, 57) + range(97, 122);
$codes_lenght = (count($ascii_codes)-1);
shuffle($ascii_codes);
$string = '';
for($i = 1; $i <= $length; $i++){
$previous_char = $char ?? '';
$char = chr($ascii_codes[random_int(0, $codes_lenght)]);
while($char == $previous_char){
$char = chr($ascii_codes[random_int(0, $codes_lenght)]);
}
$string .= $char;
}
return str_shuffle($string);
}
?>
qeremy [atta] gmail [dotta] com ¶
12 years ago
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); // i�eymrŢekr �
echo str_shuffle_unicode($str); // Şr mreyeikâ
Anonymous ¶
5 years ago
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;
}
wmtrader at yandex dot ru ¶
4 years ago
Unshuffle, using:
<?php
$string = "Hello World!";
$seed = 1234567890;
mt_srand($seed);
echo $sh = str_shuffle($string); //print 'eloWHl rodl!'
echo str_unshuffle($sh, $seed); //print 'Hello World!'
?>
<?php
function str_unshuffle($str, $seed){
$unique = implode(array_map('chr',range(0,254)));
$none = chr(255);
$slen = strlen($str);
$c = intval(ceil($slen/255));
$r = '';
for($i=0; $i<$c; $i++){
$aaa = str_repeat($none, $i*255);
$bbb = (($i+1)<$c) ? $unique : substr($unique, 0, $slen%255);
$ccc = (($i+1)<$c) ? str_repeat($none, strlen($str)-($i+1)*255) : "";
$tmp = $aaa.$bbb.$ccc;
mt_srand($seed);
$sh = str_shuffle($tmp);
for($j=0; $j<strlen($bbb); $j++){
$r .= $str{strpos($sh, $unique{$j})};
}
}
return $r;
}
Anonymous ¶
10 years ago
str_shuffle isn't recommendable for passwords. Each character exists only one time).
A function like the following one is better for this.
<?php
function generatePassword($length = 8) {
$possibleChars = "abcdefghijklmnopqrstuvwxyz";
$password = '';
for($i = 0; $i < $length; $i++) {
$rand = rand(0, strlen($possibleChars) - 1);
$password .= substr($possibleChars, $rand, 1);
}
return $password;
}
?>
CygnusX1 ¶
17 years ago
To cobine functionality and simplicity of the two functions below we can have:
<?php
function generatePasswd($numAlpha=6,$numNonAlpha=2)
{
$listAlpha = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
$listNonAlpha = ',;:!?.$/*-+&@_+;./*&?$-!,';
return str_shuffle(
substr(str_shuffle($listAlpha),0,$numAlpha) .
substr(str_shuffle($listNonAlpha),0,$numNonAlpha)
);
}
?>
Anonymous ¶
14 years ago
Shuffle for all encoding formats
<?php
function unicode_shuffle($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 $s;
}
?>
kundanborakb at gmail dot com ¶
4 years ago
<?php
//get random string with your desire length
function getRandom($length){
$str = 'abcdefghijklmnopqrstuvwzyz';
$str1= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
$str2= '0123456789';
$shuffled = str_shuffle($str);
$shuffled1 = str_shuffle($str1);
$shuffled2 = str_shuffle($str2);
$total = $shuffled.$shuffled1.$shuffled2;
$shuffled3 = str_shuffle($total);
$result= substr($shuffled3, 0, $length);
return $result;
}
echo getRandom(8);
//output -->
//GATv3JPX
//g7AzhDtR
//DTboKtiL
//CuWZR4cs
//tmTXbzBC
?>
krzysiekpiasecki at gmail dot com ¶
9 years ago
/**
* 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 $startWith;
};
testShuffleString();
echo shuffleString("Hello"); // > 'elHol' (something like this)
echo shuffleString("World!", "Hello "); // > 'Hello do!lrW' (something like this)
dzafel at op dot pl ¶
17 years ago
Very, very simple random password generator, without using rand() function:
<?php
function random_password($chars = 8) {
$letters = 'abcefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';
return substr(str_shuffle($letters), 0, $chars);
}
?>