https://www.pbainbridge.co.uk/2023/08/sort-through-array-of-duplicates-with.html

Sort through an array of duplicates with Sets.gs

/*
Function to sort through an array of duplicates, to then create a new array of
unique values.
*/

function sortArray() {

  // array to sort
  var messyArray = ['A', 'B', 'A', 'C', 'B', 'B', 'B'];

  // JavaScript 'Set' used to go through and create new unique array
  var uniqueArray = [
    ...new Set(messyArray)
  ];

  // log the unique array
  Logger.log(uniqueArray);

}