immutable js update a key in Map

Question

So I have an Immutable js map:

{
 title: "item 1",
 title2: "item 2",
 title3: "item 3"
}

I want to update the keys, so it will become:

{
  new title: "item 1",
  title2: "item 2",
  title3: "item 3"
}

so far with update() and set() I can only update the values? Is it possilbe to update the key or do I need to convert it before I can update the keys?

Answer 1

you can use mapKeys as :

var map = Immutable.Map({
  new title: "item 1",
  title2: "item 2",
  title3: "item 3"
});

map = map.mapKeys(k => {
  if (k === "title1") 
    return "newTitle";
  return k;
});

Answer 2

another, more direct, approach is to use delete

var map = Immutable.Map({
  title: "item 1",
  title2: "item 2",
  title3: "item 3"
});

map = map.set('new title', "item 1")
    .delete('title');

or

map = map.set('new title', map.get('title'))
    .delete('title');