JSFiddle - React, Tailwind, and code Playground

by brombomb

JavaScript

function flattenArray(arr) {
	'use strict';
  
	var flat = [];
  
  for (var i in arr) {
  	// Detect Objects and not strings
    if (typeof arr[i] === 'object' && arr[i].length) {
      flat.push(...flattenArray(arr[i]))
    } else {
    flat.push(arr[i]);
    }

  }
  return flat
}

//var a = [[1,2,[3]], 4]
//var a = [];
//var a = undefined;
//var a = null;
var a = [[1,2,[3]], [4, 5, [6]]]
var b = flattenArray(a)

console.log(a);
console.log(b);