JavaScript, get one object key name knowing the second

Question

Let's say I have an object that has two key-values:

let object = {name: "abc", id: 12}

But let's say, I don't know one of the key-names, so:

let object = {<unknown_to_me>: "abc", id: 12}

How can I get the first key name if I know the other one? Their positions

THe first one is reachable via:

object.id

Can I get the other one by positions, the ! operator,...?

Do you know any part of the property name? – evolutionxbox May 17 '22 at 10:03 — evolutionxbox, May 17 '22 at 10:03

yousoumar · Answer 1 · 2022-05-17T09:54:45.240

0

You could do so:

let object = {name: "abc", id: 12};
let knownKeyName = "id";

let objectKeys = Object.keys(object);
let unknownKeyName = objectKeys[objectKeys.length - 1 - objectKeys.indexOf(knownKeyName)];

console.log(unknownKeyName)

edited May 17 '22 at 09:54

answered May 17 '22 at 08:57

yousoumar

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What if I don't know their positions? id and name could be like this: let object = {id: 12,name: "abc"} – NoDiggityNoDoubt May 17 '22 at 09:02
But you only have two key-value in the object ? – yousoumar May 17 '22 at 09:03
Yes... If I switch positions on your example, it logs 12 and I don't want that...I could do it with a if-else, but I wanted to know is there a easier solution – NoDiggityNoDoubt May 17 '22 at 09:07
Okay, I just edited my answer, take a look please. – yousoumar May 17 '22 at 09:08

JavaScript, get one object key name knowing the second

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