Comparing values from an object and an array to get output from the array

Solution 1:

Not sure there is a "best" way because it very much depends on the shape of your data. But what you have isn't far off.

It seems like a small helper function might make this more extensible. Something like

var current_data = ['true', 'visiting-today', 'DVM-Wiessman','J-001'];

const VET_INDEX = 2
const RESULT_INDEX = 3

var dog_database = [
  {"dog_name": "Joey",    "chip_id": "001", "breed": "mixed",  "vets":['DVM-Wiessman','DVM-White']},
  {"dog_name": "Max",     "chip_id": "002", "breed": "beagle", "vets":'DVM-Wiel'},
  {"dog_name": "Izzy",    "chip_id": "003", "breed": "mixed",  "vets":'DVM-James'},
  {"dog_name": "Frankie", "chip_id": "004", "breed": "terrier","vets":'DVM-Smith'},
  {"dog_name": "Star",    "chip_id": "005", "breed": "husky",  "vets":['DVM-Johns','DVM-Pearson']},
  {"dog_name": "Goku",    "chip_id": "006", "breed": "lab",    "vets":'undecided'},
];


function findByVet(vetName) {
  return dog_database.find((row) => row.vets == vetName || row.vets.includes(vetName))
}

if (findByVet(current_data[VET_INDEX])) {
   console.log( current_data[RESULT_INDEX] )
} else {
   console.log( "does not exist" )
}

As you can see I added a couple constants to explain/show what each field in current_data is supposed to represent. Not sure that RESULT_INDEX is really the right name but I'm sure you could make that more informative/better named.

Not sure how much control you have over the current_data, but if that were an object, more like

var current_data = {
   "something": true, 
   "status": "visiting-today"
   "vet": "DVM-Wiessman",
   "result": "J-001"
}

(I'm sure the keys here are not correct... just guessing at what they might be called)

Then the code would be a little easier to read and understand because it'd look something like

if (findByVet(currentData.vet)) {
   return currentData.result;
} else {
   return "does not exist"
}

or something along those lines.