COOKIE Operation Guide in PHP

PHP is a very commonly used back-end development language, and its function of operating COOKIE is also very powerful. This article will provide you with a guide to COOKIE operation in PHP to help you master this function.

1. What is COOKIE

Before understanding the operation of COOKIE, we need to first understand what COOKIE is. COOKIE refers to HTTP COOKIE, which is a type of data that can be stored in the client browser. Specifically, when the client browser initiates a request to the server for the first time, the server can send COOKIE data to the browser by setting the Set-Cookie field in the response header information. After that, the browser sends COOKIE data to the server every time. When making a request, the COOKIE data will automatically be carried in the request header information.

2. The role of COOKIE

COOKIE has many functions in practical applications, such as:

1. Saving of user login status: After the user logs in successfully, the server can Send a COOKIE containing the user's login information to the user's browser. After that, every time the user visits the website, the browser will bring the COOKIE back to the server. The server can know the user's login by parsing the COOKIE. state.

2. Save user browsing history: Websites can use COOKIE to record page information that users have browsed, thereby providing users with more intelligent recommendation services.

3. Save user personalized settings: For example, website users can use COOKIE to save their own theme, language and other personalized settings to improve user experience.

3. COOKIE Operation Guide

Next, we will introduce the specific operation of COOKIE in PHP.

1. Set COOKIE

The function to set COOKIE in PHP is setcookie, and its syntax is as follows:

bool setcookie(string $name [, string $value [, int $ expire [, string $path [, string $domain [, bool $secure = false [, bool $httponly = false ]]]]]]])

Among them, $name represents the name of COOKIE, $value Indicates the value of COOKIE, $expire indicates the expiration time of COOKIE (in seconds), $path indicates the path of COOKIE, $domain indicates the domain name of COOKIE, $secure indicates whether COOKIE is transmitted only through HTTPS, and $httponly indicates whether COOKIE can only be transmitted by HTTP protocol access.

For example, the following code sets a COOKIE with the name "username", the value is "tom", and the validity period is 1 hour:

setcookie("username", "tom", time()+3600);

2. Get COOKIE

Get The operation of COOKIE is very simple, just use the $_COOKIE array. The subscript of this array is the name of the COOKIE, and its value is the value of the COOKIE. For example, the following code will obtain the value of the COOKIE named "username" and output it:

echo $_COOKIE["username"];

It should be noted that the $_COOKIE array only contains the COOKIE data sent by the client to the server. In other words, the $_COOKIE array does not contain COOKIE data that may be set by the server in the current request. If you need to obtain this type of COOKIE data, you can use the corresponding function to operate.

3. Delete COOKIE

The method of deleting COOKIE is also very simple. You only need to set the expiration time of the corresponding COOKIE to before the current time. For example, the following code will delete a COOKIE named "username":

setcookie("username", "", time()-3600);

It should be noted that deleting a COOKIE will not immediately delete the corresponding COOKIE data from the client browser, but will expire it. Before the time is set to the current time, the client browser will automatically delete the COOKIE data the next time it visits the website.

4. Conclusion

Through the introduction of this article, everyone has learned how to operate COOKIE in PHP, which is very important for websites that require user status management and personalized services. . I hope this article is helpful to everyone, thank you for reading!

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