How to stringify new Map()?

Question

I have the following code:

const x = new Map([['key', 'value']])

Now, I want to stringify this. I used the following:

JSON.stringify(x)

...which gave me an empty object.

How do you actually perform the stringification on new Map()? Is it something like you first turn it into an object and then stringify it?

I am expecting the output to be {"key": "value"}.

@ThanveerShah I thought `Map` & `Object` are similar so I was expecting object sort of output. — Axel, Mar 22 '19 at 12:30

score 3 · Answer 1 · answered Mar 22 '19 at 12:29

3

You could get the array from the map and stringify the result.

const x = new Map([['key', 'value']])

console.log(JSON.stringify(Array.from(x)));

answered Mar 22 '19 at 12:29

Nina Scholz

I was expecting output to be `{"key": "value"}` as `Object` and `Map` are similar. Isn't this how it should be or not? – Axel Mar 22 '19 at 12:32
@Sanjay try -> `[...m.entries()].reduce((a, v) => (a[v[0]] = v[1],a), {});` – Keith Mar 22 '19 at 12:33
@Keith So you've got to loop and stuff everytime. This sucks but thanks a lot for the solution. – Axel Mar 22 '19 at 12:35
it is exactly in the format, you can take it as whole map for the constructor. – Nina Scholz Mar 22 '19 at 12:35

score 0 · Answer 2 · answered Mar 22 '19 at 12:31

0

If you want to access direct value then you can use this in loop.

console.log(JSON.stringify(x.get('key')));

answered Mar 22 '19 at 12:31

Sachin Shah

2 Answers2