What is the preferred way to write boolean expressions in Java

Question

I have always written my boolean expressions like this:

if (!isValid) {
  // code
}

But my new employer insists on the following style:

Answer 1

I prefer the first style because it is more natural for me to read. It's very unusual to see the second style.

One reason why some people might prefer the second over another alternative:

if (isValid == false) { ... }

is that with the latter you accidentally write a single = instead of == then you are assigning to isValid instead of testing it but with the constant first you will get a compile error.

But with your first suggestion this issue isn't even a problem, so this is another reason to prefer the first.