[Android] shared preferences for data storage

Android provides four data storage methods:

• Shared preferences: used to store data in the "key"-"value" format. It is a lightweight key-value storage mechanism that can only store basic data types.
• Filws: file storage
• SQLite: a standard database provided by android that supports SQL statements
• Network: stores and obtains data through the network.

Shared preferences is mainly used to save system configuration information. For example, when a user logs on, the user name and password are entered, and the input content is retained at the next login.

Files stores all the things to be saved in the file. If necessary, you can obtain them by reading the file.

SQLite is an open-source relational database that can store a large amount of data and easily add, delete, modify, and query data.

The data stored in the preceding methods is private to the application. To use the data in other applications, you must use the contentproviders (Data Sharing) provided by Android ).

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