javascript array map to sort based on a field code example

Example 1: javascript sort object by key

function sortObjectByKeys(o) {
    return Object.keys(o).sort().reduce((r, k) => (r[k] = o[k], r), {});
}
var unsorted = {"c":"crane","b":"boy","a":"ant"};
var sorted=sortObjectByKeys(unsorted); //{a: "ant", b: "boy", c: "crane"}

Example 2: javascript sort array of object by property

function sortByDate( a, b ) {
  if ( a.created_at < b.created_at ){
    return -1;
  }
  if ( a.created_at > b.created_at ){
    return 1;
  }
  return 0;
}

myDates.sort(sortByDate);//myDates is not sorted.