Question

Given that b is a boolean variable, are the expressions (!b) and (b==false) the same?

Here’s where I’m at so far with this question:

• !b — returns a [FALSE response if b is true] or a [TRUE response if
  b is false].

• Declaring a boolean variable, ‘b’, in this case, would set it to
  true, therefore making !b return false.

I suppose all I need to complete the question is to know whether or not b is initially true, which I assume it to be?

Hopefully this makes sense and someone can clear this up for me?

EDIT:
This is a question from my tutor. I am asked to decide if this statement is true or false:
“The expressions (!b) and (b==false) are equivilaent, where b is a boolean variable”

Here is here extremelly helpful cryptic clue when I asked for some help:

The situation with !b is that these expressions should provide the same result for all values of b in order for the statement to be correct. Ie if b is false, then both expressions give the same result and if b is true then both expressions give the same result. You need to look at both expressions.

Answer 1

Yes, they are equivalent in “sane” languages 🙂 (let’s say Java, C++, C#)

In Javascript if b can only be true or false, it is correct (but beware! if (!null) is true, if (null == false) is false. The same for undefined)

Be aware that not all languages use ! for NOT and == for EQUALS. For example in C you would probably use int instead of bool and FALSE instead of false, but the result would be the same (but note that in C, non-zero is “true”)