php实现文件下载功能的流程分析

<?php
$_SESSION['user'] = ‘user1′;
session_unset();
session_destroy();
?>

$names = array("Peter","Quagmire","Joe");

$names[0] = "Peter";
$names[1] = "Quagmire";
$names[2] = "Joe";可以在脚本中使用这些 ID 键：

<?php

$names[0] = "Peter";
$names[1] = "Quagmire";
$names[2] = "Joe";

echo $names[1] . " and " . $names[2] . " are ". $names[0] . "'s neighbors";
?>

$ages['Peter'] = "32";
$ages['Quagmire'] = "30";
$ages['Joe'] = "34";可以在脚本中使用 ID 键：
<?php

$ages['Peter'] = "32";
$ages['Quagmire'] = "30";
$ages['Joe'] = "34";

echo "Peter is " . $ages['Peter'] . " years old.";
?>以上脚本的输出：
Peter is 32 years old.

<?php
$arrayHash = array();
foreach($arrayN as $nameN) {
   // 本行执行了 N 次。
   $arrayHash[$nameN] = 1;
}
 

foreach($arrayM as $keyM => $nameM) {
   if (isset($arrayHash[$nameM])) {
   // 本行执行了 M 次！
   unset($arrayM[$keyM]);
   }
}
return $arrayM;
?>

多维

<?php
$array[] = array("age"=>20,"name"=>"li");
$array[] = array("age"=>21,"name"=>"ai");
$array[] = array("age"=>20,"name"=>"ci");
$array[] = array("age"=>22,"name"=>"di");
 
foreach ($array as $key=>$value){
 $age[$key] = $value['age'];
 $name[$key] = $value['name'];
}
 
array_multisort($age,SORT_NUMERIC,SORT_DESC,$name,SORT_STRING,SORT_ASC,$array);
print_r($array);
?>

var http_request=false;
  function send_request(url){//初始化，指定处理函数，发送请求的函数
    http_request=false;
//开始初始化XMLHttpRequest对象
if(window.XMLHttpRequest){//Mozilla浏览器
  http_request=new XMLHttpRequest();
  if(http_request.overrideMimeType){//设置MIME类别
    http_request.overrideMimeType("text/xml");
  }
}
else if(window.ActiveXObject){//IE浏览器
  try{
   http_request=new ActiveXObject("Msxml2.XMLHttp");
  }catch(e){
   try{
   http_request=new ActiveXobject("Microsoft.XMLHttp");
   }catch(e){}
  }
    }
if(!http_request){//异常，创建对象实例失败
  window.alert("创建XMLHttp对象失败！");
  return false;
}
http_request.onreadystatechange=processrequest;
//确定发送请求方式，URL，及是否同步执行下段代码
    http_request.open("GET",url,true);
http_request.send(null);
  }
  //处理返回信息的函数
   function processrequest(){
   if(http_request.readyState==4){//判断对象状态
     if(http_request.status==200){//信息已成功返回，开始处理信息
   document.getElementById(reobj).innerHTML=http_request.responseText;
  }
  else{//页面不正常
   alert("您所请求的页面不正常！");
  }
   }
  }
   function checkfourm(obj){
    var f=document.fourm;
    var newfourm=f.newfourm.value;
    var username=f.username.value;
    var id=f.id.value;
    if(username==""){
           document.getElementById(obj).innerHTML="<img src=images/false.gif> <font color=red>您必须先登录！</font>";
     return false;
    }
    else if(newfourm==""){
     document.getElementById(obj).innerHTML="<img src=images/false.gif> <font color=red>您还没填写评论内容！</font>";
     return false;
    }
    else{
     document.getElementById(obj).innerHTML="正在发送数据...";
     send_request('sendnewfourm.php?username='+username+'&newfourm='+newfourm+'&id='+id);
     reobj=obj;
    }
   }

<table width="100%" border="0" cellspacing="0" cellpadding="0">
      <tr>
        <td align="center"><?php echo $rows_p[p_info];?></td>
      </tr>
      <tr>
        <td align="center"><br><br><iframe frameborder="0" scrolling="auto" src="showfourm.php?picid=<?=$id;?>" style=HEIGHT:250px;VISIBILITY:inherit;WIDTH:98%;Z-INDEX:2 ></iframe>
</td>
      </tr>
      <tr>
        <td align="center"><br><br>
  <div align="center" id="result"></div>
  <form name="fourm">
  <table width="100%" border="0" cellspacing="0" cellpadding="0">
          <tr>
            <td height="25"> 快速发表评论<span class="STYLE1">（必须先登陆）用户名：
                <input name="username" type="text" value="<?=$username?>" readonly>
            </span></td>
          </tr>
          <tr>
            <td height="32" align="center" valign="middle"><textarea name="newfourm" class="f" id="newfourm"></textarea></td>
          </tr>
          <tr>
            <td height="32"> <input name="submit" type="button" value="发表评论" onClick="checkfourm('result')">
              <input name="reset" type="reset" id="reset" value="重新填写">
            <input name="id" type="hidden" id="id" value="<?php echo"$id";?>"></td>
          </tr>
        </table>
        </form>
        </td>
      </tr>
    </table>