Accessing an "instance" without an instance?

So, I'm thinking of creating a JFrame without making an instance of it.

This is how I normally do it:

package framecanvasagain;

public class Framecanvasagain {

    public MyFrame theframe;

    public static void main(String[] args) {
        //creates the frame normally
        theframe = new MyFrame();

        //now let's say I want to access the frame again later on
        theframe.setLocationRelativeTo(null);
    }
    
}

I could create a JFrame without creating an instance of it, but is there a way to access that JFrame later on?

package framecanvasagain;

public class Framecanvasagain {

    public static void main(String[] args) {
        new MyFrame(); //Netbeans says "New Instance Ignored" but it still loads a JFrame

        //now let's say I want to access the frame again later on
        MyFrame().setLocationRelativeTo(null); //this returns an error, "cannot find symbol"
    }
    
}

The simple answer is no. You need to set it to a variable in order to access it's properties again.

 new MyFrame(); 

creates an instance of the JFrame but the Java garbage collector picks it up right away since it isn't set to anything.

you could do this :

(new MyFrame()).setLocationRelativeTo(null);

However, you would still be creating an instance of it and wouldn't be able to access its properties again. There is no way to reuse an object without creating it and then storing it in Java. The perils of an object orientated programming language.

Making it into a singleton might be an alternative.

https://www.geeksforgeeks.org/singleton-class-java/

Although, I don't think that's really what you are trying to do here.

Your question title is incorrect:

What you are actually asking is:
Can I access an instance without a reference to it?

And the answer is: no, you can not!

In your example code you do create an instance of JFrame but you immediately discard the reference to it, so you have no way of addressing that particular instance.

Also, it may be garbage collected at any time (unless some internal part of the library is also holding a reference to it, I am not an expert in AWT internals), so your frame could disappear at random.

But the real question is: what are you trying to achieve here?

You can do what you're asking by just adding a single word...static. Just make your myFrame variable static. Here's your first example, modified a bit. I moved the "do later" call into another method just to stress the point that your MyFrame can be accessed from anywhere:

package framecanvasagain;

public class Framecanvasagain {

    public static MyFrame theframe;

    public void someOtherMethod() {
        //now let's say I want to access the frame again later on
        Framecanvasagain.theframe.setLocationRelativeTo(null);
    }

    public static void main(String[] args) {
        //creates the frame normally
        theframe = new MyFrame();

        ....

    }
}