What are the methods of localstorage?

The methods of localstorage are: 1. setItem, store data in localstorage; 2. getItem, retrieve data from localstorage; 3. removeItem, delete specified data from localstorage; 4. clear, clear localstorage All data; 5. key, get the key name of the specified index position in localstorage; 6. length, get the number of stored data, etc.

# Operating system for this tutorial: Windows 10 system, Dell G3 computer.

Localstorage is a mechanism provided by HTML5 to store data on the client side. It can store and retrieve data in the browser without relying on the server. Localstorage provides some methods to manage stored data. Some common methods are introduced below.

1. setItem(key, value): This method is used to store data in localstorage. It accepts two parameters, the first parameter is the key name of the data to be stored, and the second parameter is the value of the data to be stored. The stored data will be saved in localstorage in the form of key-value pairs.

2. getItem(key): This method is used to retrieve data from localstorage. It accepts one parameter, which is the key name of the data to be retrieved, and returns the corresponding value. If the specified key name does not exist, the getItem method will return null.

3. removeItem(key): This method is used to delete the specified data from localstorage. It accepts one parameter, which is the key name of the data to be deleted. If the specified key name does not exist, the removeItem method will have no effect.

4. clear(): This method is used to clear all data in localstorage. Calling the clear method will delete all data stored in localstorage but will not affect data stored by other websites or applications.

5. key(index): This method is used to obtain the key name of the specified index position in localstorage. It accepts one parameter, which is the index value of the key name to be obtained, and then returns the corresponding key name. Index values ​​start from 0. If the specified index value is out of range, the key method will return null.

6. length: This attribute is used to obtain the amount of data stored in localstorage. The length attribute returns an integer indicating the number of data stored in localstorage.

In addition to the above methods, localstorage also has some other methods, such as variants of the setItem and getItem methods, such as setItemSync and getItemSync, which can store and retrieve data in synchronous mode. In addition, localstorage also supports events, such as storage events, which can monitor changes in data in localstorage.

To summarize, localstorage provides a simple and powerful set of methods to manage client-side stored data. Through these methods, we can easily store, retrieve, delete and clear data, as well as obtain the quantity and key name of the stored data. This makes localstorage a very useful tool when developing web applications.

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