let array1 = [1 ,2, 3, {}, [4, [5,6]], [ function () {}, "magic", true, ["no",false,[[[[5]]]] ] ], [1,2,[3,4,[6,[7,[8]]]]], [[[[[[0]]]]]] ]; //using recursion const flattenArray = (array, result = []) => { //go through the array for(var i = 0; i < array.length; i++) { //if the item is an array... if(Array.isArray(array[i])) { //recurse through it.. flattenArray(array[i], result); } else { //else pass it into result result.push(array[i]); } } return result; } console.log(flattenArray(array1));