This Java code demonstrates basic object-oriented programming principles. It includes a `Main` class with methods to set and display object properties. The `Helper` class showcases object interaction, highlighting encapsulation and method usage.

Main.java

public class Main {
    int x;

    public Main(int x) {
        this.x = x;
    }

    public Main() {
        this(10);
    }

    public void foo() {
        Helper.doSomethingWith(this, 42);
    }

    public void setX(int x) {
        this.x = x;
    }

    @Override
    public String toString() {
        return "Main Object with x=" + x;
    }

    public static void main(String[] args) {
        Main myObj = new Main(5);
        myObj.foo();
    }
}

class Helper {
    public static void doSomethingWith(Main mainObj, int newX) {
        System.out.println("Original object: " + mainObj);
        mainObj.setX(newX);
        System.out.println("Object after changing x: " + mainObj);
    }
}