I'm a little confused; what's going on in the part of the main if condition afte...

sago · on June 6, 2016

'obviously'?

The code looks fine to me, c.f.:

    $ node
    > undefined || undefined || 4
    4
    > undefined || 9 || 4
    9

The || operator evaluates to the first of its two operands if it is truthy, or its second operand otherwise

    > undefined || false
    false
    > false || undefined
    undefined

So:

    > e = {keyCode:9}
    > e.which || e.charCode || e.keyCode
    9