JavaScript delete keeps "empty" in Object [duplicate]

Question

Trying to delete elements from object using delete , but while the value is gone, there's still "empty" in the object. as show in the image:

which causing unwanted behviour in a following iteration:

for (const [key, value] of ids.entries()) {
    if (Object.values(this.widget_ids).indexOf(value) >= 0) {
        delete ids[key]
    }
}

now, i can't use pop or shift since . i need the option to remove by key, any idea how can i delete and remove this empty slot? or even better, remove while not having do deal with it at all?

I think you need this: stackoverflow.com/questions/2003815/… — Sergeon
– Sergeon, Commented Jan 2, 2018 at 11:51
You are using an array, thats why the index you delete keeps an empty value. Use an object instead, look at my example: image.prntscr.com/image/HmwM_SViSAuoO9qNTbSZEQ.png — user4051844
– user4051844, Commented Jan 2, 2018 at 11:53

Nina Scholz · Accepted Answer · 2018-01-02 11:56:17Z

10

You could use Array#splice, which allows to delete at a given index an amount of elements.

delete deletes the element and leaves a sparse array at this index, but it does not changes the lenght of the array.

var ids = [322, 324, 435];

ids.splice(0, 1);
//         ^     index
//            ^  count of elements to delete

console.log(ids);

edited Jan 2, 2018 at 11:56

answered Jan 2, 2018 at 11:52

Nina Scholz

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1 Comment

Jordi Castilla Over a year ago

just an add on, as OP seems to want to delete by id: use indexOf(key) in the splice function....

freelancer · Accepted Answer · 2018-01-02 11:53:36Z

0

Use splice instead of delete, it just set undefined

var ids = [1,2,3];
console.log(ids);
ids.splice(1,1);
console.log(ids);

answered Jan 2, 2018 at 11:53

freelancer

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Comments

Rohit Agrawal · Accepted Answer · 2018-01-02 11:58:50Z

0

The problem with delete is that it deletes the object property, but will not reindex the array or update its length. This makes it appears as if it is undefined or empty.

splice(start, deleteCount) removes the element from the array:

var ids = [322, 324, 435];
ids.splice(ids.indexOf(322), ids.indexOf(322) + 1);
console.log(ids);

edited Jan 2, 2018 at 11:58

answered Jan 2, 2018 at 11:52

Rohit Agrawal

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