How to loop an array to find paired numbers referenced in another array?

Question

Given a reference array of individual numbers and paired numbers in nested arrays.

How would you loop over a data set to determine which numbers are part of a pairing and output them to a new array?

// reference array
let refData = [[1,4],3,10,[8,9],6];

// example 1 data to process 
let dataSet = [1, 6, 4, 3];

// expected new outputted array
newData[[1,4],6,3];


// example 2 data to process 
let dataSet = [3, 9, 10, 6, 8];

// expected new outputted array
newData[3,[9,8],10,6];

EDITED:

Thank you for your answers.

Based on the responses I attempted to apply this to my working example, but I'm getting a little stuck. Could you please provide me with a little more help to get me over the hill?

  // Stored reference data
  let invitedGuests = [[9254,9256], 9258, 9261, [9259,9262]];

  // Dynamic received data
  let guestsArrived = [9254, 9258, 9261, 9256];

  let checkedInGuests = []

  for (let i = 0; i < invitedGuests.length; i++) {
    if (Array.isArray(invitedGuests[i])) {
      for (let j = 0; j < invitedGuests[i].length; j++) {
        for (let g = 0; g < guestsArrived.length; g++) {
          if (playerGroups[i][j] == guestsArrived[g]) {
            checkedInGuests[i][j] = guestsArrived[g];
          }
        }
      }
    }

I'm hoping to end up with

 checkedInGuests = [[9254,9256], 9258, 9261]

Iterate over array. If iterated item is array - iterate over it. — u_mulder
– u_mulder, Commented Feb 20, 2018 at 17:21
What if dataSet contained only one of the pairs? it contains 8 but not 9? — Gratus D.
– Gratus D., Commented Feb 20, 2018 at 17:22

Tung · Accepted Answer · 2018-02-20 19:43:26Z

1

Hint: use Array.isArray(item) to check whether an item is single value or array.

refData.forEach(function(item) { 
   if (Array.isArray(item)) {
      checkDataSet(item);
   } else {
      checkItemNormally(item);
   }
});

Example: Below is what I have tested.

var refData = [[1,4],3,10,[8,9],6];
        //var dataSet = [1, 6, 4, 3];
        var dataSet = [3, 9, 10, 6, 8];
        var result = [];

        refData.forEach(function (item) {
            if (Array.isArray(item)) {
                for (var i = 0; i < dataSet.length; i++) {
                    if (item.includes(dataSet[i])) {
                        result.push({
                            key: item,
                            value: item
                        });
                        break;
                    }
                }
            } else {
                // individual
                if (dataSet.includes(item)) {
                    result.push({
                        key: item,
                        value: item
                    });

                }
            }
        });
        result.forEach(function (item) {
            console.log(item.key)
        });

Hope this helps you sorting the problem out.

edited Feb 20, 2018 at 19:43

answered Feb 20, 2018 at 17:29

Tung

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3 Comments

kai Taylor Over a year ago

Thank you for your answer! I have tried to use your hint, but am struggling a bit. Would you be able to have a look at my added edited attempt above and let me know where I am going wrong?

Tung Over a year ago

@kaiTaylor: the snippets work fine, have you tried it yet?

kai Taylor Over a year ago

Thank you, I was able to apply your answer to my issue. It works great! Sorry I wasn't able to get to the finish line on my own from your first hint. Thanks again!

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