Option Array, locating and returning array with correct criteria

Question

I have an object db that has one field containing SKU's that correspond to another object that contains different venues.

db.SKU = [1002,1005,1001,1008,1007];

I then have another object listing the different venues and their details;

db.venueDB = [
        {
            SKU         : 1001,
            active      : 1,
            round       : 1,
            date        : "02/03/2026",
            country     : "Germany"
        },
        {
            SKU         : 1002,
            active      : 1,
            round       : 2,
            date        : "23/04/2026",
            country     : "Czechia"
        },{
            SKU         : 1003,
            round       : 3,
            active      : 1,
            date        : "05/05/2026",
            country     : "United Kingdom"
        },{
            SKU         : 1004,
            round       : 5,
            active      : 1,
            country     : "Spain",
            date        : "20/07/2026"
        },{
            SKU         : 1005,
            round       : 6,
            active      : 1,
            country     : "Sweden",
            date        : "21/07/2026"
        },{
            SKU         : 1006,
            active      : 1,
            round       : 7,
            country     : "Brazil",
            date        : "01/98/2026"
        },{
            SKU         : 1007,
            active      : 1,
            round       : 8,
            country     : "Latvia",
            date        : "08/09/2026"
        },{
            SKU         : 1008,
            round       : 9,
            active      : 1,
            country     : "Denmark",
            date        : "12/10/2026"
        }
    ]

Using the db.SKU I want to query db.venueDB to see if the SKU matches, and push that too a new filtered array containing the new details - in this case the new filtered array would be the venues with the SKU's, 1002, 1005, 1001, 1008 & 1007.

I know with this amount of data I could use a simple for/next loop but I have scaled down the data for this example.

I am not sure what is best or quickest way to do this, either using reduce or filter but unsure how to put this into practice.

Answer 1 · 2025-11-24 19:29:06Z

mykaf

• Nov 24 at 19:29

Reduce() returns a single value, so I think that's probably not what you are looking for. Where are you stuck with using filter()?

Answer 2 · 2025-11-24 19:32:48Z

using reduce or filter

Neither. Build up a lookup dictionary/map from your objects by SKU, then map over the SKU array. Add a filter step if you are not guaranteed to have a matching SKU.

const venueBySku = db
  .venueDB
  .values()
  .map((venue) => [venue.SKU, venue]);

const lookup = new Map(venueBySku);

const result = db.SKU
  .filter(sku => lookup.has(sku))
  .map(sku => lookup.get(sku));
  
console.log(result);

<script>
const db = {};

db.venueDB = [
    {
        SKU         : 1001,
        active      : 1,
        round       : 1,
        date        : "02/03/2026",
        country     : "Germany"
    },
    {
        SKU         : 1002,
        active      : 1,
        round       : 2,
        date        : "23/04/2026",
        country     : "Czechia"
    },{
        SKU         : 1003,
        round       : 3,
        active      : 1,
        date        : "05/05/2026",
        country     : "United Kingdom"
    },{
        SKU         : 1004,
        round       : 5,
        active      : 1,
        country     : "Spain",
        date        : "20/07/2026"
    },{
        SKU         : 1005,
        round       : 6,
        active      : 1,
        country     : "Sweden",
        date        : "21/07/2026"
    },{
        SKU         : 1006,
        active      : 1,
        round       : 7,
        country     : "Brazil",
        date        : "01/98/2026"
    },{
        SKU         : 1007,
        active      : 1,
        round       : 8,
        country     : "Latvia",
        date        : "08/09/2026"
    },{
        SKU         : 1008,
        round       : 9,
        active      : 1,
        country     : "Denmark",
        date        : "12/10/2026"
    }
];

db.SKU = [1002,1005,1001,1008,1007];
</script>

If you really need to, you can also use .reduce() to create the map, but seems a bit over the top:

const lookup = db.venueDB
    .reduce(
        (acc, venue) => acc.set(venue.SKU, venue), 
        new Map()
    );

Answer 3 · 2025-11-24 19:32:52Z

twinlakes

• Nov 24 at 19:32

// put in a set for O(1) membership checks
const skus = new Set(db.SKU)

// filter the database results by rows that have a SKU in `skus`
const result = db.venueDB.filter((row) => skus.has(row.SKU))

Answer 4 · 2025-11-24 20:54:02Z

I can find one index using db.SKU but not sure how to or the correct code to find all the indexes

Using this code:

const venueBySku = db
  .venueDB
  .values()
  .map((venue) => [venue.SKU, venue]);

const lookup = new Map(venueBySku);

const result = db.SKU
  .filter(sku => lookup.has(sku))
  .map(sku => lookup.get(sku));
  
console.log(result);

But how would I then add additional filters, i.e also check that the active and return round number.

Thanks.

Answer 5 · 2025-11-24 21:38:21Z

mykaf

• Nov 24 at 21:38

What debugging steps have you take with this code that only finds one index? Is venueBySku what you expect it to be? I don't think db.venueDB.values() returns what you think it does.

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Option Array, locating and returning array with correct criteria

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