I would say the second one, because short-circuit evaluation is awesome; it helps you write concise, bloat-free code.
I'll let Wikipedia do the talking:
Short-circuit evaluation, minimal evaluation, or McCarthy evaluation (after John McCarthy) is the semantics of some Boolean operators in some programming languages in which the second argument is executed or evaluated only if the first argument does not suffice to determine the value of the expression: when the first argument of the
ANDfunction evaluates tofalse, the overall value must befalse; and when the first argument of theORfunction evaluates totrue, the overall value must betrue.
This holds true even in JS:
conditional && expression, expression isn't evaluated unless the conditional is true.conditional || expression, expression isn't evaluated unless the conditional is false.