Is it normal to create instances all the time and use them 1 time?

Question

Java

Is it normal when an instance of a class is created in order to call its method once, and its reference is not stored anywhere?
Example:
new Window("Hello!").show();
Or:

double x = 1.0, double y = 1.0, double z = 1.0;
SomeClass.createObject(new Point(x, y, z)); // Создаётся экземпляр точки, и никуда не записывается. Используется 1 раз

Answer 1

Is normal.
But it affects performance/memory costs.
If for your specific task this is all insignificant and the impact is minimal - use it for health.
After all, programmers' time is worth more than computer hardware.
Re-optimization is not always worth the candle.

Answer 2

No, not normal. And why did you take that the instance of the point is not written anywhere? He seems to be sitting in SomeClass.

public class Someclass{
    private Point point;
    public void CreateObj(Point point){
        this.point = point;//ссылка на поинт, злой сборщик не придет.
}
}

Answer 3

Everything is very simple. If you need this instance of someone else, then write it to a variable, that's all.
In general, IDEA will even "discolor" this variable, if you don't use it anywhere. So that

double x = 1.0, double y = 1.0, double z = 1.0;
Point point = new Point(x, y, z);
SomeClass.createObject(point);

Or already go to the end))
And then you created variables for the coordinates, but you don’t want to for the instance.

Answer 4

Well...
If we talk about performance, then everything depends on the limitations of your system. Might or not, it's up to you.
If we talk about the "principle of least surprise", then I can say that you surprised me.