Java class method and instance method, java class Method Instance

Java class method and instance method, java class Method Instance

1. When a method is declared, the instance method without the keyword static is added before the method type, and the class method or static method is added.

2. The instance method can operate both class variables and instance variables, while the static method can only operate on class variables (static varival.

3. Methods in a class can call each other, and instance methods can call other methods of this class. Class methods can only call class methods of this class, but cannot call instance methods.

4. Class methods cannot be overwritten, but they can be redefined in the subclass.