Question

我有一个PHP函数，可以生成给定长度的字母数字字符串。功能正常。但生成的字符串有时包含数字，有时它不包括数字。我希望字符串每次都必须由数字和alpha组成。需要提出建议。这是函数的代码：

public static function GenerateAlphaNumString($length=0) {
        $characterPool = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
        $randomString = '';

        for ($i = 0; $i < $length; $i++) {
            $randomString .= $characterPool[rand(0, strlen($characterPool) - 1)];
        }

        return $randomString;
    }

Answer 1

一个完整的例子，提供灵活性：

<?php

class StringGenerator
{
  private $characterPool = [
    'numeric' => '0123456789',
    'alpha' => 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
  ];

  function generateRandomString($length, $pool) {
    $randomString = '';
    for ($i = 0; $i  < $length; $i++) {
      $randomString .= $this->characterPool[$pool][rand(0, strlen($this->characterPool[$pool]) - 1)];
    }
    return $randomString;
  }

  function generateAlphaNumString($length=0, $numeric=0) {
    return str_shuffle(
      $this->generateRandomString($numeric, 'numeric') .
      $this->generateRandomString($length-$numeric, 'alpha')
    );
  }
}

$generator = new StringGenerator;
for ($c=0; $c<=10; $c++) {
  var_dump($generator->generateAlphaNumString(10, 5));
}

输出类似于：

string(10) "J5F4FQX480"
string(10) "Z2g647pO9a"
string(10) "159Mf8GEL3"
string(10) "B5P57I42hN"
string(10) "Us97v5cg80"
string(10) "34VEHY825t"
string(10) "V6Ei5p06s1"
string(10) "YS5noD5127"
string(10) "4dJ4Y4G4q4"
string(10) "C8V7W3Q2G9"
string(10) "gu28g99H9d"

Answer 2

这应该可以解决问题

$characterPool = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
$randomString = '';
$numberscount = rand(1,$length-1);
for ($i = 0; $i < $numberscount; $i++) {
    $randomString .= rand(0,9);
}
for ($i = 0; $i < ($length - $numberscount); $i++) {
    $randomString .= $characterPool[rand(0, strlen($characterPool) - 1)];
}

当$ length = 1时，它总是打印一个字符。

Answer 3

你可以这样做：

// Add a quick exit:
if ($length <= 0) return '';

// Produce all characters except the last one: 
for ($i = 0; $i < $length-1; $i++) {
    $randomString .= $characterPool[rand(0, strlen($characterPool) - 1)];
}

// Check if string contains a digit, if not, reduce range 
// for generating last character so it can only be a digit:
$lastRange = preg_match("/\d/", $randomString) ? strlen($characterPool) : 10;
// choose random position, and insert last character in there:
$randomString = substr_replace($randomString, $characterPool[rand(0, $lastRange-1)], 
                               rand(0, $length-1), 0);

return $randomString;

此方法将保持每个字符出现的概率尽可能接近原始字符。它不会强制将数字组合在一起。

显然，只有当给定长度至少为2时，才能生成正确的混合。

Answer 4

在返回字符串

之前添加以下内容

If(!preg_match( '/([0-9]+)/', $randomString) {
     return self::GenerateAlphaNumString($length);
}

如果你的字符串中没有数字，只需调用相同的函数，直到有。

在PHP中生成字母数字字符串

4 个答案: