map.update(props)

Sets each value in props to a property on this map instance named after the corresponding key in props, effectively merging props into the Map. Properties not in props will be set to undefined.

import {DefineMap, DefineList} from "can";

const MyMap = DefineMap.extend({
  list: DefineList,
  name: "string"
});

const obj = new MyMap({
  list: ["1", "2", "3"],
  foo: "bar"
});

obj.update({
  list: ["first"]
});

console.log( obj.serialize() ); //-> { list: ["first"] }
console.log( obj.foo ); //-> undefined

Note: .update will remove or change properties that are not in props. Use .assign() to avoid replacing all of a map’s values.