What does this mean?: x || x === {}

Question

Does the following:

x || x === {}

not mean !!x, that is, x is defined?

Answer 1

That comparison makes no sense, because either x is truthy, then you get the result of x, or falsy, you get false (a falsy value is never strict equal to an empty object instance).

A concise version would be

x || false

for give me x or false.