private package

1. Encapsulation is to hide as many properties and methods in a class as possible, so that external programs cannot directly access them, but indirectly access them through the provided public methods.

2. Steps of encapsulating implementation
1) Use private to modify attributes and methods
2) Provide public getXxx()/setXxx() methods
3) In getXxx()/setXxx() methodsJudgment on the data

3. What are the access modifiers for classes and their scopes
Public: Shared access level, can be accessed anywhere
Default modifier: Package-level private, accessible within the same package

4. Access modifiers for class members
public, protected, default modifier, private