How to get the value of a key from json in flutter? - flutter

Question

In my API I need to get the value from the "value" key of the readm pair.
"extra_info": [
{
"name": "readme",
"value": "**In this session, we will work on different activities using Toggle Board:**\nIdentify animals using characteristics\nRecognize the animals by listening to a song"
},
{
"name": "skill",
"value": "Play school"
},
{
"name": "sub_skill",
"value": "Toggle board"
}
],
I tried using like this but some case the index number will change.
hotsLevelController.other_list[0].extraInfo[0].value;

Answer 1

Probably you have a json response which is come from HTTP request.
so this can help you:
final response = await http.get(url, headers: headers);
if (response.statusCode == 200) {
final jsonResponse = json.decode(response.body) as Map<String, dynamic>;
List<dynamic> itemsList = jsonResponse['extra_info'] as List<dynamic>;
// print values
for (var item in itemsList) {
print((item as Map<String, String>)['value']);
}
}

Answer 2

Basic JSON serialization in Flutter is very simple. Flutter has a built-in dart:convert library that includes a straightforward JSON encoder and decoder.
You can learn from here: https://docs.flutter.dev/development/data-and-backend/json
or you can use this function:
// findKey will me 'readme' in your case
// pass the json data iin json
findValue(dynamic json, String findKey) {
final data = json.decode(json) as Map<String, dynamic>;
List<Map<String, String>> items = data['extra_info'] as List<Map<String, String>>;
for (var item in items) {
if (item['name'] == findKey) {
return item['value'];
}
}
return null; //not found
}