I found out that for some reason, Angular parser (which is used e.g. to evaluate ngShow conditions) treats [false] and [0] (and their string counterparts: ['false'] and ['0']) as not true. This seems like a bug to me, because not empty array should never be treated as false in my opinion - even if it contains only falsy values.

On the other hand, [undefined] and [null] are treated as truthy. Same with arrays containing more than 1 element (['false', '0'], for example).

Browsers: Firefox 28, Chrome 34
OS: Ubuntu
Angular version: 1.2.16, 1.3.0-beta.5
Reproduction: Plunkr