isError = isError || false;

[NickFitz]

If you think JS and the browser DOM can be a pain now, just have a look at these JavaScript FAQs from 1996 - and that's when we only had one browser (Netscape Navigator 2) to worry about!

[minestrone]

I seem to always get dumped on javascript as has happened to me again. I don't even bother telling PMs that java and javascript are different now

Anyway, I just can't get my head around the stuff. Just seems to be layers of hacks to do stuff that can usually be done quite simply server side.

I agree that jquery/ajax stuff can be useful at times there just seems to be too much of it very badly written.

[VectraMan]

Yes, but really you'd want

while(truthiness)
{
doUpdation();
}

// falsiness now applies

Crazy language. I never thought initialising variables before you used them was much of a problem.

[Bunk]

if (truthiness)
{
doUpdation();
}

truthiness && doUpdation();

Who needs readability?

[mudskipper]

if (truthiness)
{
doUpdation();
}

[Bunk]

Does that not only work if isError is a boolean? I.e. the || operator is a boolean operator, it can only be true or false, and I'll take your word for it that undefined || false == false. But it wouldn't work if isError was 5.7.

I would have done isError == undefined ? false : isError;

Which says what it means, rather than some wierd script kiddyish hackery.

In Javascript you have something called truthiness and falsieness. It means that non-boolean variables can be either truthy or falsy which means they evaluate to true or false when used in a boolean situation.

eg. Off the top of my head, the following are falsy:

false
0
null
undefined
empty string

Everything else is truthy. So you could use:

if(response) {
do stuff
}

and assuming response is not a falsy value it should 'do stuff'.

It's an odd language but it makes sense once you get used to it.

Sort of

[VectraMan]

It means - if isError exists then keep it the same, otherwise set it to false.

Does that not only work if isError is a boolean? I.e. the || operator is a boolean operator, it can only be true or false, and I'll take your word for it that undefined || false == false. But it wouldn't work if isError was 5.7.

I would have done isError == undefined ? false : isError;

Which says what it means, rather than some wierd script kiddyish hackery.

[minestrone]

Ah, cheers, see it now.

Christ, can they not just have types like normal languages.

[Bunk]

Found the above in a line of javascript which I am not that great on.

Is there any reason to do this? Am I missing something? Some js trick?

Or can we just put this down to offshore devs?

It means - if isError exists then keep it the same, otherwise set it to false.

You see it a lot when you don't know if a variable or object has been created yet but you need it to exist so you might use:

var CUK = CUK || {};

So now you know that CUK definitely exists.

[minestrone]

Found the above in a line of javascript which I am not that great on.

Is there any reason to do this? Am I missing something? Some js trick?

Or can we just put this down to offshore devs?