Three methods of local storage

Local storage is divided into cookie、localStorage、sessionStorage

cookie

cookie Designed to communicate with the server , Instead of local storage , He was just borrowed to local storage 
cookie There are some disadvantages ： Small storage space , Maximum 4k、http The request needs to be sent to the server , Increase the amount of requested data 、 Only use document.cookie='…'  To modify the , Too simple 

localStorage、sessionStorage

 stay HTML5  in , Added a new localStorage/sessionString characteristic , This feature is mainly used as local storage , It's solved cookie  Lack of storage space (cookie Each of them cookie The storage space of is 4k),localStorage The general browser support in 5M size .

advantage ：HTML5 Designed specifically for storage , Maximum storage capacity 5M、API Simple and easy to use setItem getItem、 Not as http The request was sent

localStorage、sessionStorage Difference

localStorage The data will be stored permanently , Unless code or manually deleted 
sessionStorage  The data will only exist in the current session , browser 
 Clear if closed 
 It's usually used localStorage There will be more 

Be careful ：localStorage Only support string Type of storage