On the knowledge points of cookie attributes and the differences between webstorage and cookies?

cookie Original intention “ cookie ”, But in the computer cookie Not the original intention .Cookie It's some data , Stored in a text file on your computer .

When 【web The server 】 towards 【 browser 】 send out 【web page 】 when , After the connection is closed , The server will not record the user's information .
Cookie The purpose of this project is to solve “ How to record the user information of the client ”:

When users access web When the page is , His name can be recorded in cookie in .
The next time the user visits the page , Can be in cookie Read user access records in .

Can be JavaScript Control it ( Set up 、 Read 、 Delete )

cookie Classification and usage scenarios of ？

classification ： conversation cookie And persistence cookie

conversation cookie： If cookie Does not include due date , It can be regarded as a conversation cookie. conversation cookie Stored in memory , Never write to disk . When the browser is closed ,cookie Will be lost forever

persistence cookie: If cookie Include due date , It can be regarded as persistence cookie. On the specified expiry date ,cookie Will be removed from disk .

cookie Characteristics of , advantage ：

The requirements for data security are not high .
Share data across pages .
Storage space approx 4kb about

cookie The shortcomings of

1）cookie May be disabled ;
2）cookie Browser related , Can't visit each other ;（cookie Cross domain can achieve , Storage security risks ）
3）cookie May be deleted by the user ;
4）cookie Security is not high enough ;
5）cookie Very small storage space , about 4kb about .

Common occasions ：（1） Save user login status ;（2） Track user behavior ;（3） Custom page ;（4） Create a shopping cart … wait

cookie API

cookie Stored on the client in the form of key value pairs .

Such as ：document.cookie=“key=val; expires=Thu, 18 Dec 2043 12:00:00 GMT; path=/”;

document.cookie Used to set cookie, It is best to encapsulate as a function or use a plug-in library .
expires cookie The expiration time of
path cookie The path of
domain cookie Domain name of , cookie Object's domain Property is set cookie Scope of action , If this domain does not match the domain you are currently browsing , It can be regarded as “ The third party cookie”, Will be rejected by the browser .

More attribute references ：
cookie Properties of .png

webStorage and cookie The difference between ？

webStorage Than cookie Security
webStorage Than cookie Large amount of storage
webStorage There is no need to carry... During client and server requests , and cookie need .