Four ways to generate strings with random words in PHP

The content of this article is to share with you four methods of generating strings with random words in PHP. It has certain reference value. Friends in need can refer to it

The following introduces four basic methods of generating random strings:

Method 1:

1 , generate a random integer between 33 – 126, such as 35.

2. Convert 35 into the corresponding ASCII code character, such as 35 corresponding to #.

3. Repeat steps 1 and 2 above n times to connect to an n-digit password.

This algorithm mainly uses two functions. The mt_rand (int $min, int $max) function is used to generate random integers, where $min – $max is the range of ASCII codes, here it is 33-126, The range can be adjusted as needed. For example, 97-122 bits in the ASCII code table correspond to the English letters a-z. For details, please refer to the ASCII code table; the chr (int $ascii) function is used to convert the corresponding integer $ascii into the corresponding character.

 function create_password($pw_length =  
            { 
                    $randpwd = ”; 
                    for ($i = 0; $i < $pw_length; $i++) 
                    { 
                        $randpwd .= chr(mt_rand(33, 126)); 
                    } 
                            return $randpwd; 
              } 
                // 调用该函数，传递长度参数$pw_length = 6 
            echo create_password(6);

##Method Two:

1. Preset a string $chars, including a – z, A – Z, 0 – 9, and some special characters.

2. Randomly pick a character from the $chars string.

3. Repeat the second step n times to get a password of length n.

 function generate_password( $length = 8 ) 
       { 
                // 密码字符集，可任意添加你需要的字符        
                $chars = ‘abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()-_                   
                  []{}<>~`+=,.;:/?|&#39;;         
                  $password = ”;        
                   for ( $i = 0; $i < $length; $i++ )          {      
                        // 这里提供两种字符获取方式           
                        // 第一种是使用 substr 截取$chars中的任意一位字符；           
                        // 第二种是取字符数组 $chars 的任意元素 
          // $password .= substr($chars, mt_rand(0, strlen($chars) – 1), 1); 
          // $password .= $str{mt_rand(0,strlen($chars) - 1)};    
          //生成php随机数
            $password .= $chars[ mt_rand(0, strlen($chars) - 1) ];             }             return $password;            }

##Method Three:

## 1. Preset a character array $chars, including a – z, A – Z, 0 – 9, and some special characters.

2. Use array_rand() to randomly select $length elements from the array $chars.

3. According to the obtained key name array $keys, take out the characters from the array $chars and concatenate the string. The disadvantage of this method is that the same characters will not be retrieved repeatedly.

 function make_password( $length = 8 ) 
     {  
        // 密码字符集，可任意添加你需要的字符 
         $chars = array(‘a', ‘b', ‘c', ‘d', ‘e', ‘f', ‘g', ‘h', 
                 i', ‘j', ‘k', ‘l','m', ‘n', ‘o', ‘p', ‘q', ‘r', 's', 
                ‘t', ‘u', ‘v', ‘w', ‘x', ‘y','z', ‘A', ‘B', ‘C', ‘D', 
                ‘E', ‘F', ‘G', ‘H', ‘I', ‘J', ‘K', ‘L','M', ‘N', ‘O', 
                ‘P', ‘Q', ‘R', ‘S', ‘T', ‘U', ‘V', ‘W', ‘X', ‘Y','Z', 
             ‘0′, ‘1′, ‘2′, ‘3′, ‘4′, ‘5′, ‘6′, ‘7′, ‘8′, ‘9′, ‘!', 
                 ‘@','#', ‘$', ‘%', ‘^', ‘&', ‘*', ‘(‘, ‘)', ‘-', ‘_', 
                ‘[&#39;, &#39;]‘, ‘{‘, ‘}&#39;, ‘<&#39;, ‘>&#39;, ‘~&#39;, ‘`&#39;, ‘+&#39;, ‘=&#39;, ‘,&#39;, 
                 ‘.&#39;, ‘;&#39;, ‘:&#39;, ‘/&#39;, ‘?&#39;, ‘|&#39;); 
   
            // 在 $chars 中随机取 $length 个数组元素键名 
            $keys =array_rand ($chars, $length); 
            $password = ”; 
           for($i = 0; $i < $length; $i++) 
          { 
             // 将 $length 个数组元素连接成字符串 
              $password .= $chars[$keys[$i]]; 
          } 
            return $password; 
         }

Method 4

：## The basic idea is to encrypt md5 and generate a 32-bit stringMT_RAND generates a random number of the specified range

Time, you can get the timestamp

Use random number Current timestamp, you can get a random number that will not be repeated
code as follows:


##

 $rand = md5(time() . mt_rand(0,1000));

Supplementary

: Add a curly bracket {} after the PHP variable and fill in the numbers, which refers to the characters of the corresponding serial number of the PHP variable.

                                                                                                                                                                                        / The output is e If you want to check whether a string meets the specified length, you can consider using braces (braces) plus isset to replace the strlen function. Because isset is a language structure and strlen is a function, use isset More efficient than using strlen.

For example, to determine whether the length of a string is less than 5:

if (!isset ($str{5})) is better than if (strlen ($str) < 5).        

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