Rearranging Columns on Google Spreadsheet using Google Apps Script

function rearrangeColumns(sheet, ar) {
  var obj = ar.reduce(function(ar, e, i) {
    return ar.concat({ from: e + 1, to: i + 1 });
  }, []);
  obj.sort(function(a, b) {
    return a.to < b.to ? -1 : 1;
  });
  obj.forEach(function(o) {
    if (o.from != o.to) sheet.moveColumns(sheet.getRange(1, o.from), o.to);
    obj.forEach(function(e, i) {
      if (e.from < o.from) obj[i].from += 1;
    });
  });
}

// Please run this function.
function main() {
  var sheet = SpreadsheetApp.getActiveSheet();
  var rearrangedColumnIndexes = [4, 3, 1, 0, 2];
  rearrangeColumns(sheet, rearrangedColumnIndexes);
}