Java

I'd skip the ternary and go with

foo = Optional.ofNullable(bar)
        .map(Bar::baz)
        .orElse(null);

But if I didn't, I'd use the first form.

In java 9 there is Objects.requireNonNullElse(obj, defaultValue)

I think generally it’s preferably to work in the affirmative, i.e. bar == null? but I’ll admit I don’t stick to this 100% of the time and generally just use whatever feels better / more appropriate in the moment

If I had to go with the ternary operator, I would choose not to negate the statement for the sake of readability.

If I had free will of choice I would prefer using the Optionals API, like @MagicShel@programming.dev did.

I think the meat being more prominent in the second one is subjective. If I were writing a method to do something like this with ifs, I would handle the edge cases first and return early from them. The meat would be what's left after the edge cases. So this lines up with the first form.

The second, or early return/continue/break.

But don't forget the third option:

foo = null
if (bar != null)
    foo = bar.baz();

This is much more readable if nontrivial; the only downside is that this inhibits the practice of ubiquitous final.

Actually, doesn't Java allow lazy final if you don't initialize (that would require explicit else)? I speak too many languages ...