CODEWITHSUNDEEP
sortingflutterdictionarydart
JakesMD
JakesMD

Reputation: 2206

How to reorder map by nested values

What is the best way of sorting a map by its nested values in Dart?

Map myMap = {
  'A':{'foo':'#', 'pos':2},
  'B':{'baa':'#', 'pos':0},
  'C':{'yay':'#', 'pos':1},
}
Map mySortedMap = myMap.sort() ???
print(mySortedMap)

Output:
{
  'B':{'baa':'#', 'pos':0},
  'C':{'yay':'#', 'pos':1},
  'A':{'foo':'#', 'pos':2},
}

Upvotes: 0

Views: 217

Answers (1)

Owczar
Owczar

Reputation: 2593

There is quite simple way: sort keys and create new map from those keys:

Map sortMapByPos(Map map) {
  final sortedKeys = map.keys.toList(growable: false)
    ..sort((k1, k2) => ((map[k1]['pos'] - map[k2]['pos'])));

  return Map.fromIterable(sortedKeys, key: (k) => k, value: (k) => map[k]);
}

Usage as below:

print(sortMapByPos(myMap));

Upvotes: 1

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