PHP开发技巧（四）-获取随机字符串两种实现方法详解

<?php  
  
/** 
 * ======================================= 
 * Created by Zhihua_W. 
 * Author: Zhihua_W 
 * Date: 2016/12/1 0004 
 * Time: 下午 5:15 
 * Project: PHP开发小技巧 
 * Power: 两种方法实现获取随机字符串 
 * ======================================= 
 */  
  
/** 
 * 方法一：获取随机字符串 
 * @param number $length 长度 
 * @param string $type 类型 
 * @param number $convert 转换大小写 
 * @return string 随机字符串 
 */  
function random($length = 6, $type = 'string', $convert = 0)  
{  
    $config = array(  
        'number' => '1234567890',  
        'letter' => 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',  
        'string' => 'abcdefghjkmnpqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ23456789',  
        'all' => 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890'  
    );  
  
    if (!isset($config[$type]))  
        $type = 'string';  
    $string = $config[$type];  
  
    $code = '';  
    $strlen = strlen($string) - 1;  
    for ($i = 0; $i < $length; $i++) {  
        $code .= $string{mt_rand(0, $strlen)};  
    }  
    if (!empty($convert)) {  
        $code = ($convert > 0) ? strtoupper($code) : strtolower($code);  
    }  
    return $code;  
}  
  
/** 
 * 方法二：获取随机字符串 
 * @param int $randLength 长度 
 * @param int $addtime 是否加入当前时间戳 
 * @param int $includenumber 是否包含数字 
 * @return string 
 */  
function rand_str($randLength = 6, $addtime = 1, $includenumber = 0)  
{  
    if ($includenumber) {  
        $chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHJKLMNPQEST123456789';  
    } else {  
        $chars = 'abcdefghijklmnopqrstuvwxyz';  
    }  
    $len = strlen($chars);  
    $randStr = '';  
    for ($i = 0; $i < $randLength; $i++) {  
        $randStr .= $chars[rand(0, $len - 1)];  
    }  
    $tokenvalue = $randStr;  
    if ($addtime) {  
        $tokenvalue = $randStr . time();  
    }  
    return $tokenvalue;  
}  
  
//其中也可以放多个参数  
//random(4,'number');  
//random(6,'letter',1);  
echo random(10);  
//方法二同样  
echo rand_str(6);  
  
?>