php时间戳与字符串的相互转换

<?php    
date_default_timezone_set(“prc”);    
    
$stringtime = date(“Y-m-d H:i:s”,time());    
    
echo $stringtime.”<br/>”;    
    
echo strtotime($stringtime).”<br/>”;    
    
echo date(“Y/m/d G:i:s A”,strtotime($stringtime));    
?>