Handling Undefined Property

Question

I have an object that returns properties that are either defined or undefined.

I wish to handle these undefined properties but I keep getting an error of undefined. The following two code snippets below are what I have tried so far:

if (typeof choice.Location == "undefined") {
}

and

if (choice.Location == undefined) {

}

Edit:

To clarify, if I do something like this.

if (typeof choice == "undefined") {
}
else if (choice.Location) {
//do something 
}

I get the same error.

If you're getting that error, it's probably that `choice` itself is `undefined`. What **exactly** does the error say? — Pointy, May 30 '18 at 12:16
then choice must be undefined. please check it in developer tool — Jay, May 30 '18 at 12:18
So you're trying to get the property `Location` of something that is undefined. — Reinstate Monica Cellio, May 30 '18 at 12:18
better, you can check like this way if(choice && choice.location) — Jay, May 30 '18 at 12:19
Right then, `choice` is the problem. You have not posted enough code for the actual cause of that to be apparent to anyone. — Pointy, May 30 '18 at 12:19
Possible duplicate of [Detecting an undefined object property](https://stackoverflow.com/questions/27509/detecting-an-undefined-object-property) — Liam, May 30 '18 at 12:20
If I put something like if (choice == "undefined") {} the code will go to the next part of the statement but still throw the Location error. — sacora, May 30 '18 at 12:23
You're only checking to see if it's undefined - you're not doing anything if it's not so your code will continue. — Reinstate Monica Cellio, May 30 '18 at 12:26

Dimitrios Matanis · Answer 1 · 2018-05-30T12:40:29.600

1

You can check for both the object and then it's property.

Something simple like the following would do it:

if (typeof choice !== 'undefined' && choice.location) { ... }

edited May 30 '18 at 12:40

answered May 30 '18 at 12:19

Dimitrios Matanis

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This doesn't work for me. It gives me the same error. – sacora May 30 '18 at 12:33
2

@sacora If you want help then please read how to create a **[mcve]**. You must post some code that we can run so that we can actually see the problem, because the answers you have been given *are correct*, so your question must be wrong. Until we can reproduce the problem then you have not asked a valid question. Please don't reply to this comment. Just digest, read the link I've given you, and then fix the question or ask a new one. – Reinstate Monica Cellio May 30 '18 at 12:35
I agree with Archer but i've updated my answer to include a typeof comparison. I'm not sure what you are trying to do exactly, but this solution should work for most cases – Dimitrios Matanis May 30 '18 at 12:42
If my updated answer works for you, do you mind accepting it please? – Dimitrios Matanis May 31 '18 at 09:03

Handling Undefined Property

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