How can I refer to local storage as empty?

Question

I have a series of if and else if statements and what I want is to determine a scenario in terms of local storage being empty.

I've tried:

(if localStorage.getItem('example') == localStorage.clear()) {

//Do something if that local storage item is empty
}

I am aware the program may think I'm assigning the local storage to clear out it's contents. So would I do something like:

(if localStorage.getItem('example') == localStorage()) {

//Do something if that local storage item is empty
}

If not, how can I refer to the local storage as an empty object so the program doesn't get confused thinking that I'd like to clear the contents in the storage?

In the first case you’re clearing the localStorage every time. In the second localStorage is not a function so it can’t be called. — evolutionxbox, Oct 20 '20 at 18:51
Yes, that's why I believe that's not the way to go in terms of identifying if it's empty. — The.Epistemophile.Bibliophile, Oct 20 '20 at 18:52
Does this answer your question? [How to check whether a Storage item is set?](https://stackoverflow.com/questions/3262605/how-to-check-whether-a-storage-item-is-set) — xehpuk, Oct 20 '20 at 19:02

score 2 · Answer 1 · answered Oct 20 '20 at 18:52

2

You can check to see if it is null.

if(localStorage.getItem('example') === null){
 console.log("x");
}

answered Oct 20 '20 at 18:52

imvain2

15,480
1
16
21

Reality · Answer 2 · 2020-10-20T19:09:05.507

Ok both answers posted are right. However, I want to explain a few things that I have experienced. Undefined is returned if you are referring to the object as so and it has nothing in it:

localStorage.key; //will be undefined if not set

localStorage.getItem() returns null if nothing is in it (as I have experienced).

localStorage.getItem('key'); //will return null if not set

And yes, all you have to do is check if it is null or undefined (depending on the method you use)

if(localStorage.getItem('key') === null){
   //do stuff here
}

or

if(localStorage.key === undefined){
   //do stuff here
}

or you can use the ! operator like so:

if(!localStorage.getItem('key')){
   //do stuff here
}

or

if(!localStorage.key){
   //do stuff here
}

The reason for this is because both null and undefined are falsely values, and the ! operator checks for falsely values

score 0 · Answer 3 · answered Oct 20 '20 at 18:52

0

You can just check if localStorage.getItem() is undefined. Here's an example:

function isCleared(item) {
  return !localStorage.getItem(item)
}

answered Oct 20 '20 at 18:52

AlexH

828
7
26

How can I refer to local storage as empty?

3 Answers3