Append array to another array #javascript

combineArrays.js

/**
 * Add one array to another
 * @param  {Array} a The array to add another array to
 * @param  {Array} b The array to add to array a
 * @return {Array}   Array a with b appended to it
 */
function combineArrays(a, b) {
  a.push.apply(a, b);
  return a;
}