SharePoint JS CSOM Code to add/update Choices for a Choice Field

Following code snippet shows how to update the 'Status' column within a Tasks list and add new choice values to the field/column using JS CSOM. The Status column within a Tasks list is of type Choice Field.

var CONST_TASKS_LIST_TITLE = "Tasks";
var CONST_TASKS_LIST_COLUMN = "Status";
var strStatusValues = "Deferred,Closed,Blocked,Postponed for next Release";
var ctx = SP.ClientContext.get_current();
var listDevTasks = ctx.get_web().get_lists().getByTitle(CONST_TASKS_LIST_TITLE);
var fldStatus = listDevTasks.get_fields().getByInternalNameOrTitle(CONST_TASKS_LIST_COLUMN)
var fldStatusChoice = ctx.castTo(fldStatus, SP.FieldChoice);
ctx.load(fldStatusChoice);
ctx.executeQueryAsync(function () {
var newValues = strStatusValues.split(",");
var currentChoices = fldStatusChoice.get_choices();
for (var i = 0; i < newValues.length; i++) {
currentChoices.push(newValues[i]);
}
fldStatusChoice.set_choices(currentChoices);
fldStatusChoice.updateAndPushChanges();
ctx.executeQueryAsync(function () {
console.log("Added new choice values to the column");
}, function (sender, args) { deferred.reject(args.get_message()); });
}, function (sender, args) { deferred.reject(args.get_message()); });