Can I use the same map key several times?-CodePudding

I'm storing and retrieving data like this:

data = new Map();
data.set("key", id);
data.set("key", id2);
data.get("key");

the second set is overwriting key element. I want a structure, that can hold multiple times the key element or one key element with multiple id data pairs. Does such a collection exist in Javascript or how to achieve this?

thank you

CodePudding user response：

JS Map and no other JS structure I'm aware of allows you to have more occurences of the same key. Keys must be unique.

I think that maybe unshifting new values into an array stored in a regular object might be a good way to achieve what you want. That way, your newest value will always be the first in the array, and thus accessible at index 0, like so:

const data = {key: []};

data.key.unshift(id);
data.key[0] // value of id

data.key.unshift(id2);
data.key[0] // value of id2