PHP常用知识

1.$_SERVER

$urlshang = $_SERVER['HTTP_REFERER']; //可以得到上一页的地址
$urldan = $_SERVER['PHP_SELF']; //得到当前页面地址
$urlcan = $_SERVER["HTTP_HOST"].$_SERVER["PHP_SELF"]."?".$_SERVER["QUERY_STRING"];//这个可以得到带参数的地址
echo "1.上一页地址： ".$urlshang.'<br>';
echo "2.当前地址： ".$urldan.'<br>';
echo "3.带参地址： ".$urlcan.'<br>';

2.取模

<?php foreach($images as $k=>$v):?>
      <?php if($k%4==0):?>
          <li class="clearfix">
      <?php endif;?>        
         < a href=" ">< img src="<?php echo base_url("upload/".$v['url']."")?>" alt="" /></ a>  
     <?php if(($k+1)%4==0 || count($images)==$k+1):?>
         </li>
     <?php endif;?>
                            
 <?php endforeach;?>

 3.PHP密码函数

$pwd = "123456"
$hash = password_hash($pwd, PASSWORD_DEFAULT);
echo $hash;

if (password_verify($pwd,'$2y$10$Wt/rDUL4AB4/h9tZ3ZMpVOO46HYe9QQW6CT7BdjU6BeKCABVAI942')) { 
    echo "密码正确";
} else {  
    echo "密码错误";
}