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Map: map.has()

Indicates whether an element with a key exists.

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map.has() indicates whether an element with a key exists

  • finds nothing in an empty map
  • finds an element by it`s key
  • finds undefined as key too
  • does not coerce keys
  • after removal (using map.delete(<key>)) it doesnt find the element anymore
  • adding an item (using map.set(key, value)) later will make has() return true

Links

A video (15min) documenting how this kata was created.