Sort list with nulls

main.dart

void main() {
  print("Current list");
  var l = [1,5,2,null,0];
  print(l);
  
  print("sort it asc with nulls at the beginning");
  sortIt(l, asc:true, nullAtEnding: false);
  print(l);
  
  print("sort it asc with nulls at the end");
  sortIt(l, asc:true, nullAtEnding: true);
  print(l);
  
  print("sort it desc with nulls at the beginning");
  sortIt(l, asc:false, nullAtEnding: false);
  print(l);
  
  print("sort it desc with nulls at the end");
  sortIt(l, asc:false, nullAtEnding: true);
  print(l);
}

void sortIt(l, {bool asc = true, bool nullAtEnding = true}){
  l.sort((a, b) {
    int? result;
    if (a == null) {
      result = 1;
    } else if (b == null) {
      result = -1;
    }
    
    if (result != null) {
      result *= nullAtEnding ? 1 : -1;
    } else {
      if (asc) {
        // Ascending Order
        result = a.compareTo(b);
      } else {
        // Descending Order
        result = b.compareTo(a);
      }
    }
    return result!;
  });
}