Can I sort List<dynamic> in dart

Question

Can I sort List<dynamic> in dart?

List<dynamic> list= [9,10,'Plus One'];
list.sort();
print(list);

I expect the result like 9,10,'Plus One' Or 'Plus One', 9, 10

Answer 1

You just need to provide a callback to List.sort that orders heterogeneous types the wya you want. For example, assuming that your heterogeneous List contains only int s and String s, you could do:

  List<dynamic> list = [9, 10, 'Plus One'];
  list.sort((a, b) {
    if ((a is int && b is int) || (a is String && b is String)) {
      return a.compareTo(b);
    }

    if (a is int && b is String) {
      return -1;
    } else {
      assert(a is String && b is int);
      return 1;
    }
  });

  print(list);

If you need to potentially handle other types, you will need to adjust the callback appropriately.

Answer 2

If you want to sort dynamic list and want string before number(int or double) try

this code:

 List<dynamic> list = [
    'mahmoud',
    14,
    'zika',
    9,
    10,
    'plus One',
    5,
    'banana',
    1,
    2.5,
    'apple',
    2,
    1.2,
    'ball'
  ];
  list.sort(
    (a, b) {
      if ((a is num && b is num) || (a is String && b is String)) {
        return a.compareTo(b);
      }
      // a Greater than b return 1
      if (a is num && b is String) {
        return 1;
      }
      // b Greater than a return -1
      else if (a is String && b is num) {
        return -1;
      }
      // a equal b return 0
      return 0;
    },
  );
  print(list);// [apple, ball, banana, mahmoud, plus One, zika, 1, 1.2, 2, 2.5, 5, 9, 10, 14]