How to Flatten an Array

Here is the instruction for this coding exercise: Create a function to flatten an array without using the Array method .flat() Given an array [1,2,[3,4, [5,6,7], 8], 9, [10, [20], 30]] The function should return [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30...