Valid false values
boolean, javascript
Solution
As per ECMA 5.1 Standards, Truthiness of an expression will be decided, as per the following table
+---------------+-------------------------------------------------------+
| Argument Type | Result |
+---------------+-------------------------------------------------------+
| Undefined | false |
+---------------+-------------------------------------------------------+
| Null | false |
+---------------+-------------------------------------------------------+
| Boolean | The result equals the input argument (no conversion). |
+---------------+-------------------------------------------------------+
| Number | The result is false if the argument is +0, −0, or NaN;|
| | otherwise the result is true. |
+---------------+-------------------------------------------------------+
| String | The result is false if the argument is the empty |
| | String (its length is zero); otherwise the result is |
| | true. |
+---------------+-------------------------------------------------------+
| Object | true |
+---------------+-------------------------------------------------------+
So, you have missed `-0` and `NaN`.
console.log(Boolean(-0));
# false
console.log(Boolean(NaN));
# false
Problem
Converting any value to `Boolean` returns `false` or `true`. For example: ``` > Boolean (false) false > Boolean (null) false > Boolean (undefined) false > Boolean ("") false ``` But `0` is special, because it's a number. I consider is as a valid false value: ``` > Boolean (0) false ``` Are there any other valid false values?