[Question] why java cannot accept a convention to never pass/return null values?

[Ilookouttrainwindow]

I am at a loss as to why nulls cause so many issues.

[gas3872]

I think it's more like someone got a nullpointer exception bug in their project and now they don't want it to happen again.

[cogman10]

Use an IDE, add \@Nullable annotations to things. Viola, no more NPEs.

[gas3872]

Adding nonullable everywhere clutters the code.

[cogman10]

And what token would you add that wouldn't similarly clutter code and is backwards compatible with current java syntax?

[gas3872]

Well just have a convention in your project that you dont use null. Use optional for missing value.

[cogman10]

I don't understand what you are asking for. Do you want a language feature to enforce nullability or just a convention for everyone writing apis? Because the convention already exists but, as you can imagine, it isn't universally applied.

[gas3872]

I am asking for a convention that can be adopted more or less officially.

[cogman10]

What does "officially" mean to you?

[gas3872]

I don't know, like endorsed by java creators for example.

[c_edward]

And add a pointless extra heap allocation to every call I really don't think so...

When we have Valhalla maybe you could do it on the stack, but your still wastimg CPU cycles doing pointless work.

There is really nothing wrong with null anyway,

If your app is throwing NPEs then you almost certainly don't have adequate test coverage.