我试图在PHP中创建一个随机字符串,我得到绝对没有输出:
<?php
function RandomString()
{
$characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
$randstring = '';
for ($i = 0; $i < 10; $i++) {
$randstring = $characters[rand(0, strlen($characters))];
}
return $randstring;
}
RandomString();
echo $randstring;
我做错了什么?
下面是一个简单的单行程序,它生成一个真正的随机字符串,而不需要任何脚本级循环或使用OpenSSL库。
echo substr(str_shuffle(str_repeat('0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', mt_rand(1,10))), 1, 10);
把它分解,这样参数就清楚了
// Character List to Pick from
$chrList = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
// Minimum/Maximum times to repeat character List to seed from
$chrRepeatMin = 1; // Minimum times to repeat the seed string
$chrRepeatMax = 10; // Maximum times to repeat the seed string
// Length of Random String returned
$chrRandomLength = 10;
// The ONE LINE random command with the above variables.
echo substr(str_shuffle(str_repeat($chrList, mt_rand($chrRepeatMin,$chrRepeatMax))), 1, $chrRandomLength);
此方法的工作原理是随机重复字符列表,然后打乱组合的字符串,并返回指定的字符数。
您可以进一步随机化它,通过随机化返回字符串的长度,将$chrRandomLength替换为mt_rand(8,15)(用于8到15个字符之间的随机字符串)。
我想要特定字符和预设长度的伪随机字符串。我希望当前版本的PHP具有最高质量的伪随机性,此时它可以是v5、v6、v7或v8,并且可以使用默认配置或特殊配置。为了解决这种混乱,我在这里选取了其他几个答案,并包含了函数可用性条件。
使用。要全局使用它,给$VALID_ID_CHARS赋值你想要的字符,然后调用它:
$VALID_ID_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
$myNewRandomId = makeId(6);
function makeId($desiredLen)
{
global $VALID_ID_CHARS;
if ($desiredLen < 1) {
throw new \RangeException("Length must be a positive integer");
}
$vLen = 0;
if (function_exists('mb_strlen')) {
$vLen = mb_strlen($VALID_ID_CHARS, '8bit') - 1;
} else {
$vLen = strlen($VALID_ID_CHARS) - 1;
}
if (function_exists('random_int')) {
$pieces = [];
for ($i = 0; $i < $desiredLen; ++$i) {
$pieces[] = $VALID_ID_CHARS[random_int(0, $vLen)];
}
return implode('', $pieces);
}
if (function_exists('openssl_random_pseudo_bytes')) {
$random = openssl_random_pseudo_bytes($desiredLen);
$id = '';
for ($i = 0; $i < $desiredLen; ++$i) {
$id .= $VALID_ID_CHARS[ord($random[$i]) % $vLen];
}
return $id;
}
http_response_code(500);
die('random id generation failed. either random_int or openssl_random_pseudo_bytes is needed');
}
function randomName($length = 8) {
$values = array_merge(range(65, 90), range(97, 122), range(48, 57));
$max = count($values) - 1;
$str = chr(mt_rand(97, 122));
for ($i = 1; $i < $length; $i++) {
$str .= chr($values[mt_rand(0, $max)]);
}
return $str;
}