ES6 Create an array of array that contains pairs

Question

I have the following data model. I'm trying to array reduce and create pairs of objects from it. Also, if there is an odd number i'll add that to the last pair.

Given data:

const pairs = [ {name: bob, value: foo}, {name: jane, value: foo}, {name: mary, value: foo}, {name: elizabeth, value: foo}, {name: colin, value: foo}]

Would like to get the following output:

const pairs = [ 

    [{name: bob, value: foo}, {name: jane, value: foo}],
    [{name: mary, value: foo}, {name: elizabeth, value: foo}, {name: colin, value: foo}]
]

What i've tried so far is:

const result = pairs.reduce((acc, curr, i, array) => {
    const acc = acc.length % 3 === 0 ? acc.slice(acc.length -1, acc.length) : acc.push(curr);
    return acc
}, []);

Is there a simple way to do this with Array.reduce()?

No, don't use `reduce` for this. [There are so many much simpler alternatives](https://stackoverflow.com/a/8495740/1048572). — Bergi, Nov 05 '18 at 17:50
There's a good example in there that uses reduce. Thanks Bergi — chrisjlee, Nov 05 '18 at 18:33

score 1 · Answer 1 · answered Nov 06 '18 at 17:29

const pairs = [
  {name: 'bob',       value: 'foo'},
  {name: 'jane',      value: 'foo'},
  {name: 'mary',      value: 'foo'},
  {name: 'elizabeth', value: 'foo'},
  {name: 'colin',     value: 'foo'}
];

const flooredHalf = parseInt(pairs.length / 2);
const result = new Array(flooredHalf);
for (let i = 0; i <= flooredHalf; i += 2) {
  result[i / 2] = pairs.slice(i, (i + 3 === pairs.length ? i + 3 : i + 2));
}

/* DEMO */
console.log(JSON.stringify(result));

ES6 Create an array of array that contains pairs

1 Answers1