How to take only specific indexes and map to another indexes?

Question

I need to make an api call with particular parameter.

See example below:

const apiFunc = (someId, anotherId) => apiCall(someId, anotherId) }

However in an array called someArr I get something like [1, 'someId', 2, 'anotherId', 3, 'anotherId', 4, 'someId']

I need to use in apiCall() if for example 1 (same as 4) if 'someId' is next to it, and 2 (same as 3) if 'anotherId' is next to it.

How can I properly format this please to achieve desired result?

Thanks

I have tried using .includes() but without much success.

[Chunk the array into tuples](https://stackoverflow.com/q/8495687/1048572), create a `Map` from it, then `apiCall(map.get(1), map.get(3))`. — Bergi, Jan 20 '23 at 11:45
Your question is not clear. Can you be explicit which separate `apiCall` calls you want to make (with literal arguments provided) for a sample input array? — trincot, Jan 20 '23 at 12:41

score 1 · Accepted Answer · answered Jan 20 '23 at 13:09

You could use filter to extract all values that precede "someId", and another filter call to extract all values that precede "anotherId". Then pair them when you make the api calls:

// Mock 
const apiCall = (someId, anotherId) => console.log(someId, anotherId);

const arr = [1, 'someId', 2, 'anotherId', 3, 'anotherId', 4, 'someId'];

// Extract the "someId" values
const someId = arr.filter((val, i) => arr[i+1] == "someId");
// Extract the "otherId" values
const otherId = arr.filter((val, i) => arr[i+1] == "anotherId");
// Iterate the pairs of someId, otherId:
for (let i = 0; i < someId.length; i++) {
    apiCall(someId[i], otherId[i]);
}

Oh that is what the OP wanted? I would never have guessed. – Bergi Jan 21 '23 at 00:38 — Bergi, Jan 21 '23 at 00:38

score 0 · Answer 2 · answered Jan 20 '23 at 12:05

0

You can create a simple function like this:

const getId = (array, number): string | null => {
  const index = array.indexOf(number);

  if (index === -1 || index === array.length - 1) {
    return null;
  }

  return array[index + 1];
};

and then use it like so:

const id1 = getId(someArr, 1);  // 'someId'
const id2 = getId(someArr, 3);  // 'anotherId'

apiCall(id1, id2);

answered Jan 20 '23 at 12:05

Yuriy Yakym

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In my example i can have many of these occurrences. How can I adjust to that? I need to map `someId` to what it belongs to and same with `anotherId`. – Mister Mister Jan 20 '23 at 12:07
1

I'm not sure if I understand what you mean. `getId(someArr, 4)` will return 'someId'; – Yuriy Yakym Jan 20 '23 at 12:08
Can you please elaborate what you want to achieve? Just describe input and expected output. – Yuriy Yakym Jan 20 '23 at 12:14

How to take only specific indexes and map to another indexes?

2 Answers2