CODEWITHSUNDEEP
javascripthashhashmapcomparehashtable
Rob
Rob

Reputation: 63

using two hash tables to identify similarities in javascript

I am trying to use hash tables to compare my magazine array below with my notes array. I look at the problem and see that it could be done in other ways but I am trying to specifically learn how to use hash tables. I want to see if magazine has the same words within it as notes. My idea is to end up with something like this and then compare them

magazineHash = {
    "cool": 2,
    "needs": 1,
    "some": 1,
    "for": 1,
    "work": 1
}

and the same for notes array and then to compare the frequencies (values) of the words

magazine = ["cool", "needs", "some", "for", "work", "cool"];
notes = ["cool", "needs", "for", "cool", "work"]

function reliableNote(magazine, note){

}

There is so much info and variety in what people talk about regarding hash tables online, I am getting very confused! Any help would be awesome!

Upvotes: 0

Views: 103

Answers (1)

J. Pichardo
J. Pichardo

Reputation: 3115

If you want to map an array to an object/hash table you could use the reduce function:

const magazine = ["cool", "needs", "some", "for", "work", "cool"];
const notes = ["cool", "needs", "for", "cool", "work"]


function mapToHash(arr) {
  return arr.reduce((hash, entry) => ({ ...hash,
    [entry]: hash[entry] ? hash[entry] + 1 : 1
  }), {})
}

console.log(mapToHash(magazine));
console.log(mapToHash(notes));

Upvotes: 1

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