var test =a||b;

I often saw a variable assignment like this:

var onComplete = onComplete || false;


My understanding: if onComplete is valid, return the value of ocComplete; otherwise, return false.

--Is this correct understanding?

--If so, how to determine if the onComplete is valid or not? Use onComplete ==null or else?


Thanks


Scott

--If so, how to determine if the onComplete is valid or not? Use onComplete ==null or else?

|| operator:

http://www.javascriptkit.com/jsref/comparison_operators.shtml


If the first expression does NOT evaluate to true (ie: it's null or undefined), then the value of the second expression is evaluated and returned.


best regards