Get random names using time and mt_rand function

This knowledge will be used in file uploading and other occasions. I haven’t learned object-oriented yet, so now I present it to you in functional form

<?php
/**
 * Created by PhpStorm.
 * User: Administrator
 * Date: 2016/9/19 0019
 * Time: 19:47
 */
function rdname(){
    $t = getdate();
    $year=$t[&#39;year&#39;];
    $month = $t[&#39;mon&#39;]<10? "0".$t[&#39;mon&#39;]:$t[&#39;mon&#39;];
    $day = $t[&#39;mday&#39;]>9?$t[&#39;mday&#39;]:"0".$t[&#39;mday&#39;];
    $hour= $t[&#39;hours&#39;]>9?$t[&#39;hours&#39;]:"0".$t[&#39;hours&#39;];
    $min = $t[&#39;minutes&#39;]>9?$t[&#39;minutes&#39;]:"0".$t[&#39;minutes&#39;];
    $sec = $t[&#39;seconds&#39;]>9?$t[&#39;seconds&#39;]:"0".$t[&#39;seconds&#39;];
    $randnum=mt_rand(1000,9999);//获取随机的4个数字
    $randname=$year.$month.$day.$hour.$min.$sec.$randnum;//把年月日时分和随机数拼接起来
   return $randname;//返回新的名字
}
$newname=rdname();//把返回的名字赋值给$newname
echo $newname; ?>

Effect display: