Java中静态和非静态嵌套类的区别

// Java Program to illustrate
// static nested class
// Importing input output classes
import java.io.*;
// Importing all classes from
// java.util package
import java.util.*;
// Class 1
// Helper class1
class ClassA {
    // Static variable
    static int x = 10;
    int y = 20;
    // Static variable with privare
    // access modifier in ClassA
    private static int z = 30;
    // Class 2 - Nested static class
    // Helper Class 2
    static class ClassB {
        // Method of nested static class
        void get()
        {
            // Execution statements whenever
            // function is called
            // Print and display commands
            System.out.println("x: " + x);
            System.out.println("z: " + z);
        }
    }
}
// Class 3
// Main Class
class GFG {
    // Main driver method
    public static void main(String[] args)
    {
        // Creating an object of static nested class
        // defined outside Main class
        ClassA.ClassB ob1 = new ClassA.ClassB();
        // Calling the method od static nested class
        // in main() method
        ob1.get();
    }
}


x: 10
z: 30


// Importing all input output classes
import java.io.*;
// Class 1
// Helper Class 1
class ClassA {
    // Static member variable of ClassA
    static int x = 10;
    int y = 20;
    public int z = 30;
    // Class 2 - Helper Class 2
    // Non-static nested class
    class ClassB {
        // Method of Non-static nested class
        void get()
        {
            // Execution command of get() method
            // Print and display commands
            System.out.println("x: " + x);
            System.out.println("y: " + y);
            System.out.println("z: " + z);
        }
    }
}
// Class 3
// Main Class
class GFG {
    // Main driver method
    public static void main(String[] args)
    {
        // Creating object of Class 1 in main() method
        ClassA ob1 = new ClassA();
        // Creating object of non-static nested class in
        // main()
        ClassA.ClassB ob2 = ob1.new ClassB();
        // Calling non-static nested class method
        // in main() method
        ob2.get();
    }
}


x: 10
y: 20
z: 30