Question

Say I have the class signatures

Class1(Class2 c);
Class2(Class1 c);

How do I initialize both?

Answer 1

For one of the classes, you don’t provide the reference in the constructor, but you can use a set-method instead. Initializing them both dependent on each other when none of them previously exists seems difficult.

class Foo {
    private Bar bar;
    public Foo(Bar bar) {
        this.bar = bar;
    }
}

class Bar {
    private Foo foo;
    setFoo(Foo foo) {
        this.foo = foo;
    }
}


Bar bar = new Bar();
Foo foo = new Foo(bar);
bar.setFoo(foo);

Also note that there might be better solutions to this. Such as using an Observer-pattern, it all depends on how you plan on using your objects.