Java Variables for Beginners: From Definition to Usage, Even Zero-Basics Can Understand!

This article introduces the concept and usage of variables in Java. A variable is a "data piggy bank" for storing data, which can be modified at any time to avoid repeated data entry. Defining a variable requires three parts: type (e.g., int for integers, String for text), variable name (hump naming convention is recommended, such as studentAge), and initial value (it is recommended to assign a value when defining to avoid null values). Naming rules: Java keywords cannot be used, it cannot start with a number, it can only contain letters, underscores, $, etc., and cannot be repeated within the same scope. When using, you can use System.out.println to print the value, or directly assign a value to modify it (e.g., score=92). A variable is a basic data container in Java. The core points are: definition requires type + name + value, clear naming conventions, and flexible usage. After understanding, complex functions can be constructed, making it suitable for beginners to master the basic data storage method.