How to sort map's values?

Question

Can someone give me a hint? I want to sort a map\'s values by the length of the lists.

var chordtypes = {
  \"maj\": [0, 4, 7],
  \"M7\": [0, 4, 7, 11],
  \"         


        

Answer 1

Something like this could work for you:

Map chordtypes = {
  "maj": [0, 4, 7],
  "M7": [0, 4, 7, 11],
  "m7": [0, 3, 7, 10],
  "6": [0, 4, 7, 9],
  "9": [0, 4, 7, 10, 14],
  "sus2": [0, 2, 7],
  "sus4": [0, 5, 7],
  "omit3": [0, 7],
  "#5": [0, 4, 8],
  "+7b9#11": [0, 4, 8, 10, 13, 18],
  "+9": [0, 4, 8, 10, 14]
};

List keys = chordtypes.keys.toList();
keys.sort((k1, k2) {
  if(chordtypes[k1].length > chordtypes[k2].length)
    return -1;
  if(chordtypes[k1].length < chordtypes[k2].length)
    return 1;
  return 0;
});
keys.forEach((String k) {
  print('$k ${chordtypes[k]}');
});