js local storage: localStorage

1. Introduction

　　localStorage can directly store the data requested for the first time locally, which is equivalent to a 5M -sized database for front-end pages

　　 ——Note : The localStorage attribute is only supported in IE versions above IE8 . localStorage belongs to permanent storage . If there is a lot of storage content, it will consume memory space and cause the page to become stuck.

 

2. The specific usage is as follows:

　　1. localStorage - data storage with no time limit 

　　 var arr = [1,2,3];
　　 localStorage.setItem("temp",arr); //Store parameters: 1. The value to be called 2. The data to be stored
　　 console.log(localStorage.getItem("temp"));//输出

　2. Empty localStorage
　　localStorage.clear(); //

　3. Delete key-value pairs
　　localStorage.removeItem("arr");　　

　　Note: The stored data can only be stored in the form of strings .

3. Provide the method of transferring JOSN data:

　　//JSON object to JSON string

　　var obj = {"a": 1,"b": 2};
　　obj = JSON.stringify(obj); //Convert to JSON string
　　localStorage.setItem("temp2", obj);

　　//JSON string to JSON object
　　obj=JSON.parse(localStorage.getItem("temp2"));