Converting types in flutter: Map<String,dynamic> to Map<String, double> in flutter-CodePudding

How do I convert Map<String, dynamic> To Map<String, double in Flutter>? What commands are there?

CodePudding user response：

You can use the castFrom method like this:

final output = Map.castFrom<String, dynamic, String, double>(input);

Where input is of type Map<String, dynamic> and output will be of type Map<String, double>.

CodePudding user response：

Instead of casting I prefer this way to avoid getting runtime error.

void main(List<String> args) {
  Map<String, dynamic> data = {
    "A": 3,
    "b": "4",
    "c": null,
    "d": 2.4,
  };

  final Map<String, double> result = Map.fromIterables(
    data.keys,
    data.values.map((e) => (double.tryParse(e.toString()) ?? 0.0)),
  );

  print(result); //{A: 3.0, b: 4.0, c: 0.0, d: 2.4}
}

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