javascript - Does map.set() overwrite the value if the key already exists?

I was wondering if map.set() overwrites the value if the key already exists in the map.

How can I test this easily when in a big project? Are there any website you can use for javascript coding?

I was wondering if map.set() overwrites the value if the key already exists in the map.

How can I test this easily when in a big project? Are there any website you can use for javascript coding?

Share Improve this question edited Mar 15, 2021 at 8:51 asked Jan 4, 2021 at 14:36 Jan 771 gold badge2 silver badges13 bronze badges

2 Yes – VLAZ Commented Jan 4, 2021 at 14:41
what should happen instead? – Nina Scholz Commented Jan 4, 2021 at 14:50
An exception ('key already present') – John Pool Commented Mar 12, 2021 at 13:03

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1 Answer 1

Sorted by: Reset to default 6

According to developer.mozilla on Map.set

The set() method adds or updates an element with a specified key and a value to a Map object.

I remend looking up prototype functions on native objects on developer.mozilla at first.