Falsy. It is the idea that we can infer something is true, similar to assuming.
If something does not exist (like
NaN) or has a value equating to zero, it is considered
false. For example, an empty string of
""would be considered false. It has no value.
If the data has value (other than specifically
NaN, zero, or
false) it is considered
true, because it has value. For example,
1 == '1'will result in
1 === '1'will return
falsebecause they are not exactly equal (one is a numeric value, the other a string).
NaNstands for Not a Number. Think of it like "undefined" or "does not exist". Note: division by zero gives an answer of infinity.