JavaScript Learning Notes Cookie Object_Basic Knowledge

JavaScript Cookie

Cookie object:

Cookie is a kind of user data information (Cookie data) saved in the Cookies folder of the client's hard disk in the form of a file.

The cookie file is created by the visited Web site to permanently save the session data between the client and the Web site, and the cookie data is only allowed to be read by the visited Web site.

Cookie file format:

NS: Cookie.txt

IE: username@domain name.txt

There are two types of cookies:

　(1) Persistent cookies will be stored on the client’s hard drive.

(2) Session Cookie: It will not be stored on the client's hard drive, but will be placed in the memory of the browser process. When the browser is closed, the session cookie will be destroyed.

Use JS to implement Cookie operations

Write Cookie:

　document.cookie = "keyword = value [; expires = valid date] [;...]"

Read Cookie:

Document.cookie

Delete cookies:

　document.cookie = "keyword = ; expires = current date"

Remarks:

　1. Valid date format: Wdy,DD-Mon-YY HH:MM:SS GMT

　2.Wdy/Mon: English week/month;

3. Also includes path, domain, secure attributes;

4. Each website (domain) can create 20 cookie data;

5. Each browser can store 300 cookie data, 4k bytes;

6. Customers have the right to prohibit the writing of cookie data.

Example

The above is the entire content of the cookie object in JavaScript, I hope you will like it.