CODEWITHSUNDEEP
coffeescript
Paul
Paul

Reputation: 26660

CoffeeScript: search for an object with specific property value

This is how to search for existence of value in array:

words = ["rattled", "roudy", "rebbles", "ranks"]
alert "Stop wagging me" if "ranks" in words

I am looking for similar elegance in searching for existence of object with specified property value:

words = [
  { id: 1, value: "rattled" },
  { id: 2, value: "roudy" },
  { id: 3, value: "rebbles" },
  { id: 4, value: "ranks" }
]
alert "Stop wagging me" if "ranks" in words.value

But the line at the bottom does not work.

Upvotes: 0

Views: 182

Answers (2)

matehat
matehat

Reputation: 5374

If you want a 1-liner, you can do the following:

alert "Stop wagging me" if do -> return yes for w in words when w.value is 'ranks'

The advantage is that it will iterate in the array instead of deriving a new one (memory-efficient) and it will stop the iteration as soon as it finds a match (cpu-efficient). The price to pay is that it's perhaps a bit less readable. To address that, the best way might be to make your own utility function:

inObjectMember = (obj, key, value) ->
  for o in obj when o[key] is value
    return yes

alert "Stop wagging me" if inObjectMember words, 'value', 'ranks'

Upvotes: 1

Amberlamps
Amberlamps

Reputation: 40478

I just tried following and it worked for me:

alert "Stop wagging me" if "ranks" in (word.value for word in words)

Upvotes: 1

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