'use strict'
const makeMeFlat = (arr) => {
  let output = []; //define what we want to eventually return
  if (arr && Array.isArray(arr)) { //make sure there is an input and it's an array
    for(var i = 0; i < arr.length; i++) { //Loop through input
      if (Array.isArray(arr[i])) { //The parameter is an array, we need to look into this; recursively
        output = output.concat(makeMeFlat(arr[i])); //Redefine `output` as itself with the array concactenated to it, while recursively looping through the parameter
      } else {
        output.push(arr[i]); //The parameter is not an array, send it to the output
      }
    }
  }
  return output;
};