关于PHP：PHP – 在字符串中选择5个随机字符？

PHP - Select 5 random characters in a string?

如何从给定的字符串中随机选择5个字符？他们可以重复。

假设我的字符串是：

1	static $chars ="123456789bcdfghjkmnpqrstvwxyzBCDFGHJKLMNPQRSTVWXYZ";

我只想从这个变量中提取5个随机字符。感谢任何能帮助我的人！

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function gen_code() {

$charset ="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";

return substr(str_shuffle($charset), 0, 5);
}

号

它起作用了，请试试看，

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<?php
$length = 5;
$randomString = substr(str_shuffle("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"), 0, $length);
echo $randomString;
?>

。

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只需创建5个随机索引并从字符串中获取字符：

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$chars ="123456789bcdfghjkmnpqrstvwxyzBCDFGHJKLMNPQRSTVWXYZ";
$length = strlen($chars) - 1;
$randchars = '';
for ($i = 0; $i < 5; $i++) {
$position = mt_rand(0, $length);
$randchars .= $chars[$position];
}
echo $randchars;

。

如果你只想得到一个5个字符长的随机字符串，那么有更好的方法。从操作系统中获取随机数据，然后对其进行编码，这将是理想的方法：

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function random_string($length) {
$raw = (int) ($length * 3 / 4 + 1);
$bytes = mcrypt_create_iv($raw, MCRYPT_DEV_URANDOM);
$rand = str_replace('+', '.', base64_encode($bytes));
return substr($rand, 0, $length);
}
echo random_string(5);

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//define a function
function generateRandomString($length = 5){
$chars ="123456789bcdfghjkmnpqrstvwxyzBCDFGHJKLMNPQRSTVWXYZ";
return substr(str_shuffle($chars),0,$length);
}

//usage
echo generateRandomString(5); //random string legth: 5
echo generateRandomString(6); //random string legth: 6
echo generateRandomString(7); //random string legth: 7

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$var = explode(',' , '1,2,3,4,5,6,7,8,9,a,b,c,d,f,g,h,j,k,m,n,p,q,r,s,t,v,w,x,y,z,B,C,D,F,G,H,J,K,L,M,N,P,Q,R,S,T,V,W,X,Y,Z');
$string ='';
for($i=0; $i <= 4; $i++)
{
$string .= $var[rand(0, count($var)-1)];
}

echo $string;

。

edit*有一个off-by-one错误，"count($var)"应为"count($var)-1"

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只需将您的$chars传递到此函数中，它将返回5个随机字符。

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// to generate random string

function rand_str($length = 5, $chars = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ')
{
// Length of character list
$chars_length = (strlen($chars) - 1);
// Start our string
$string = $chars{rand(0, $chars_length)};
// Generate random string
for ($i = 1; $i < $length; $i = strlen($string))
{
// Grab a random character from our list
$r = $chars{rand(0, $chars_length)};
// Make sure the same two characters don't appear next to each other
if ($r != $string{$i - 1}) $string .= $r;
}
// Return the string
return $string;
}

// function ends here

试试这个

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static $chars ="123456789bcdfghjkmnpqrstvwxyzBCDFGHJKLMNPQRSTVWXYZ";
$chars=str_shuffle($chars);
$finalString=substr($chars, 0,5);

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