Reverse sort array of numbers then delete columns in array Google App Script

Question

If I understand, if have (I get arr dynamically)

var arr = [7,2,5,1] and I sort it arr.Sort() I get [1,2,5,7]

How do I reverse sort it so I get [7,5,2,1]

function DeleteColsInList() {
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var Sheet = ss.getSheetByName('ShtName')

  var arr= [7,2,5,1];

 // reverse sort here so I can delete columns in proper order highest to  lowest
  var arrSort =arr.sort()

  for (var i = 0, length = arrSort.length; i < length; i++) {
    Sheet.deleteColumns(arrSort[i]);
   }
  }

UpDated:

function DeleteColsInList() {
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var Sheet = ss.getSheetByName('ShtName')

  var arr= [7,2,5,1];

 // reverse sort here so I can delete columns in proper order highest to  lowest
  arr.Reverse()

  for (var i = 0, length = arrSort.length; i < length; i++) {
    Sheet.deleteColumns(arr[i] + 1);
   }
  }

Answer 1

You can probably do this:

var arrSort =arr.sort();
arrSort.reverse();

I think you can even chain them:

var arrSort = arr.sort().reverse();

Per the comments, even that's more verbose than necessary. You can just do

arr.sort().reverse()

on your original array object.

(h/t to red red wine)