Simple multidimensional array flatten

flatten.js

/**
 * Flatten multidimensional Arrays
 * @param {Array} arrayToFlat multidimensional array to be flatten. 
 * @returns {Array} array flattened
 */
function flatten(arrayToFlat = []) {
  const result = []
  
  arrayToFlat.forEach(element => {
    if (Array.isArray(element)) {
      result.push(...flatten(element))
    } else {
      result.push(element)
    }
  });
  
  return result;
}