Using && as a replacement for IF statement

Question

I found the following snippet when digging through some code:

"string" != typeof myVar && (myVar = "");

I understand what happens here. If myVar is not a string, that first condition evaluates to true so the second condition is evaluated, causing myVar to be set to "". So it's essentially a replacement for the following:

if ("string" != typeof myVar)
    myVar = "";

The only discernible difference is that the former of the two strategies is also a return statement, though the code I found is not using the returned value. So I'm wondering:

1. Are there any pros or cons to either strategy?
2. If the only pro for the first strategy is the ability to return a value, is the snippet I found considered poor programming since it is more difficult to read?

Answer 1

Just want to point out there are less clear uses of this idiom and more clear.

"string" != typeof myVar && (myVar = "");

I read this and actually had to convert it to if/else in my head. Steve McConnell argued there shoud be one line of code per work, which I tend to agree with and which this is in ludicrous violation of. Also note that embedded side-effects are risky in the first place, this is pretty egregious.

parameters = parameters || {};
var speed = parameters.speed || 60;

is IMO a much clearer use, partly since it's such a well established idiom. or

if(x && x.employer && x.employer.company === 'google') 

is a clear use of the idiom (you'll get an exception if you do undefined.company, for instance).