function generalize(a) {
  if (!Array.isArray(a)) {
    throw new TypeError('Array input expected');
  }

  if (a.length === 0) {
    return a;
  }

  var b = [];

  for (var i = 0; i < a.length; i++) {
    b.push(a[i].value);
  }

  return b;
}
Remove the numeric identifier from the elements
@param {array} a  An array
@return {array} An array of values without identifiers