arrayFlatten.js

/** 
* Flattens any levels of nested arrays into single level
* @author Kader Fasid(fasidmpm@gmail.com)
* @params {Array} - Nested Array to Flatten
* @returns {Array} - Flattened array.
*/
const flatten = (input) => {
 var arr = [];
  const recursiveArr = (input) => {
    if(Array.isArray(input)) {
      input.forEach(x => recursiveArr(x));
    } else {
      arr.push(input);
    }
  }
  recursiveArr(input)
  return arr;
}