// Arbitrarily nested array
let arr = [[[[1,2],[[3,3],4],5,6]],7];
// Final array that would contain the flattened elements
let flattenedArray = [];

/*
 * @function flatten
 *
 * @args element element to be flattened or passed back to recursion
 *
 * @description if the element is an array pass each of elements to this function.
 * When the element is not an array , push this element to the flattened array
 *
 * @output flattenedArray contains the flattened form of the initial arbitrarily sized array
 */
function flatten(element) {
  if (element.constructor === Array) {
    for (let idx = 0; idx < element.length; idx++) {
      flatten(element[idx]);
    }
  } else {
    flattenedArray.push(element);
  }
}

// Call the function with the main array as the argument
flatten(arr);

// Print the final flattened array (output)
console.log(flattenedArray);