PHP study notes: Universal random string generation function (already encapsulated)

Used to make verification codes, and then encapsulate this function. When using it, you need to set 2 parameters:

　 The string to be collected in the $str setting, such as:

　$str='efasfgzsrhftjxjxjhsrth';

　 Then the string generated in the function will be randomly grabbed from efasfgzsrhftjxjxjhsrth;

　$codeLen sets the random string to be generated. If set to 5, 5 random strings will be generated.

Principle: randomly grab strings and splice the strings

Effect:

Code:

<span style="font-size: 18px;"><?php

//mt_rand  获取随机数 mt_rand(min, max);
$str="abcdefghijkmnpqrstuvwxyz0123456789ABCDEFGHIGKLMNPQRSTUVWXYZ";//设置被随机采集的字符串
$codeLen='5';//设置生成的随机数个数

function  str_rand($str,$codeLen){
    $rand="";
    for($i=0; $i<$codeLen-1; $i++){
        $rand .= $str[mt_rand(0, strlen($str)-1)];  //如：随机数为30  则：$str[30]
    }
   return $rand;
}
$code=str_rand($str,$codeLen);
echo $code;</span><br /><span style="font-size: 18px;">?></span>