Detailed explanation of how to use cookies in PHP

This article mainly introduces the use of cookies in PHP: adding/updating/deleting/getting cookies, automatically filling in the user's user name and password, and determining whether to log in for the first time. It has a good reference value. Let's take a look at it with the editor

The use of cookies in PHP---add/update/delete/get cookies and automatically fill in the user's user name and password and determine whether it is the first time to log in

What is a cookie

The server saves user information on the client, such as login name, password, etc.

These data are like cookies. The amount of data is not large. The server can read it from the client when needed and save it in the client's browser cache directory.

① When the browser accesses, cookie.php, the server will also send an http response with Set-Cookie:name=zxf;expire=Wed,21-Sep-2017 20:14 GMT. When the browser obtains the message, it will save the cookie information. To local disk

② If we don’t have time (the third parameter)

The cookie will not be saved to the client. When the browser session ends, the cookie will expire

③ The cookie saves string information

④ The client can save multiple keys=>val

⑤ During the saving process of the cookie, Chinese will be urlencoded

Cookies can have multiple key=>val, and different key values ​​can be assigned different validity times

The code is as follows: xx.php

<?php
//添加cookie
setcookie("name","zxf",time()+3600);
//数组

/$arr = array(1,2,3); 
 $arr_str = serialize($arr); 
 setcookie("a",$arr_str,time()+3600); 

//获取cookie
 
var_dump($_COOKIE);

//更新cookie

setcookie("name","aaa",time()+3600);

//删除cookie

setcookie("name","",time()-20);

//删除所有

foreach ($_COOKIE as $key => $value) {
 setcookie($key,"",time()-1);
 }
echo "成功";
 ?>

If the key=>val of the cookie you delete is not deleted, the cookie will be retained on the client. If you delete all the cookies on this website, the browser will delete the cookie file

Determine whether it is the first time to log in

<?php

//先判断cookie里是否有上次的登录信息

if(!empty($_COOKIE[‘lastVisit&#39;])){

  echo “你上次登陆的时间是”.$_COOKIE[‘lastViat&#39;];

//更新时间

setcookie(“lastVisit”,”data(Y-m-d H:i:s)”, time()+3600);

}else{

//说明用户是第一次登陆

echo”第一次登陆”;

//更新时间

setcookie(“lastViait”,”data(“Y-m-d H:i:s”)”, time()+3600);

}
?>

When you open the login interface, automatically fill in the user name and password

checklogin.php

//获取用户是否选中了保存id

if(!empty($_POST[‘cookie'])){

  setcookie(“id”,$id,time()-100);

}else{

  if(!empty($_COOKIE[‘id'])){

   setcookie(“id”,$id,time()-10);

}
}

The above is the entire content of this article, I hope It will be helpful to everyone’s study.

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