Sometimes, we want to split an array into array pairs in JavaScript.

In this article, we’ll look at how to split an array into array pairs in JavaScript.

Split an Array into Array Pairs in JavaScript

To split an array into array pairs in JavaScript, we can use the JavaScript array’s reduce method.

For instance, we can write:

const initialArray = [2, 3, 4, 5, 6, 4, 3, 5, 5]
const newArr = initialArray.reduce((result, value, index, array) => {
  if (index % 2 === 0) {
    return [...result, array.slice(index, index + 2)];
  }
  return result
}, []);
console.log(newArr)

We have the initialArray that we want to split into chunks of 2.

To do this, we call reduce with a callback that returns the result array that’s created from the result array spread into a new array and an array with the next 2 items in the list if index is event.

We get the next 2 items with the slice with index and index + 2 as the indexes.

Otherwise, we just return result.

The 2nd argument is an empty array so result is always an array.

As a result, newArr is:

[
  [
    2,
    3
  ],
  [
    4,
    5
  ],
  [
    6,
    4
  ],
  [
    3,
    5
  ],
  [
    5
  ]
]

Conclusion

To split an array into array pairs in JavaScript, we can use the JavaScript array’s reduce method.