Getting clear with special conditional statement

Question

I will show you a little part of my app where I am wondering which is the proper way to put a conditional I am working on. If both ways I will show you are correct, I would like you to tell me the consequences/adversities

if ((some.thing === '' || 0) || (some.how === '' || 0)) {
      //something is going on here
}

that is how I have it so far, is there something bad with it?

or should be better this way:

if ((some.thing === '' || some.thing === 0) || (some.how === '' || some.how === 0)) {
       //something is going on here
}

so what are your suggestions ? is it the same result at the end?

EDIT

Adding another way:

if (some.thing === '' || some.thing === 0 || some.how === '' || some.how === 0) {
       //something is going on here
}

Answer 1

The || operator has precedence over the comparison operators.

So some.thing === '' || 0 is the same as (some.thing === '') || (0). It:

• will evaluate to 0 if some.thing === '' is false or
• will evaluate to true if some.thing === '' is true.

Look at this example (as running in a JavaScript console):

> some = { thing: 0 }
  Object { thing: 0 }
> some.thing === ''
  false
> some.thing === '' || 0  // this is like false || 0
  0
> some = { thing: '' }
  Object { thing: "" }
> some.thing === ''
  true
> some.thing === '' || 0  // this is like true || 0
  true

Prefer something like the last expression you wrote.

EDIT: Actually both '' and 0 are falsy in JavaScript, so you can just simply write your complete expression as:

if (!some.thing || !some.how) {
  //something is going on here
}

Answer 2

This part looks fishy to me:

some.thing === '' || 0

Do you mean this instead:

some.thing === '' || some.thing === 0

0 is always falsy, so the expression some.thing === '' || 0 is always equivalent to some.thing === ''

EDIT

You need the final expression:

(some.thing === '' || some.thing === 0 || some.how === '' || some.how === 0)