JSFiddle - React, Tailwind, and code Playground

by Yuvraj Dhakate

JavaScript

function flatten(arr) {
  const newArr = arr.reduce((acc, item) => {
    if (Array.isArray(item)) {
      acc = acc.concat(flatten(item));
    } else {
     acc.push(item);
    }

    return acc;
  }, []);

  return newArr;
}
const numArr = [1, [2, [3], 4, [5, 6, [7]]]];
var x flatten(numArr) // [1, 2, 3, 4, 5, 6, 7]