Apparently this line of code is triggering "Object expected":
var bPid = (b != null && typeof (b.processId) == "number") ? b.processId : 0;
Unfortunately I can't step through the code in the debugger since this is an intermittent error that shows up in a Windows SideShow gadget that I'm writing. But, I'd imagine someone should be able to tell me how it's even possible to get object expected given all the checks that I'm doing to attempt to prevent something like that.
It seems b is not an object, so I'd alert(b) before that line to see if it's been assigned a value at all.
Even if it has a value assigned, it may not be an object, so you might as well ask for typeof(b) == 'object'.
b != null catch that? (Note that I'm not using strict equality ===.)
b is undefined, it short-circuits at b != null, since undefined == null (even though undefined !== null).
typeof is an operator and not a function. See developer.mozilla.org/en/Core_JavaScript_1.5_Reference/…You are calling b.processId without making sure that b is an object.
typeof(b.processId) == "number" prevent me from calling b.processId in the case of, say, b = 3?
typeof(b.processId) makes JavaScript evaluate b.processId. In case of b being the number 3, this would result in "undefined". In case of b being undefined itself, it would result in an error.typeof was to let you test if some property existed without actually dereferencing it. But, Firebug agrees that typeof(undefined.processId) gives an error, so I guess not >_<.
Your variable b probably doesn’t exist. Try this:
var bPid = (typeof b != "undefined" && typeof b.processId == "number") ? b.processId : 0;
var bPid = (b && typeof b.processId == "number") ? b.processId : 0; do? After all, both null and undefined evaluate to false.b was a declared variable with an undefined value.The safest (and the shortest) way to check if the b variable is 'truthy' (in Douglas Crockford's terms) would be
var bPid = (b && typeof (b.processId) == "number") ? b.processId : 0;
unless you explicitly want to compare it to null (in which case you should compare with === that doesn't do type coersion).
And to be 'truthy' a varible is anything except false, null, undefined, NaN, the number zero, or an empty string.
