Flutter get json data by index

Question

I'm using Flutter and I have a JSON like below:

var json = {
  "key1": {"key": [1,2,3]},
  "key2": {"key": [4,5,7]},
  "key3": {"key": [8,9,10]},
}

I know that, for example, I can retrieve {"key": [4,5,7]} just by calling json["key2"].

But i'm asking, is it possible to retrieve it by using its index position, just like json[1]?

@someuser Actually "key1", "key2" etc, are sample key names for this example. In reality, the "key1", "key2" etc, are unique id values. — we_mor
– we_mor, Commented Dec 1, 2020 at 16:35

Teddichiiwa · Accepted Answer · 2020-12-01 16:58:24Z

1

Yes, change your json to:

{
  "values": [
    {
      "key": [1,2,3]
    },
    {
      "key": [4,5,7]
    },
    {
      "key": [8,9,10]
    }
  ]
}

And access it like: parsedJson["values"][0]

In case you don't want to change your data structure, you can still do it like:

import 'dart:core';

void main() {
  var json = {
  "key1": {"key": [1,2,3]},
  "key2": {"key": [4,5,7]},
  "key3": {"key": [8,9,10]},
  };
  
  List<Map<String, List<int>>> jsonObjects = [];
  
  for (final name in json.keys) {
    final value = json[name];
    print('$value');
    jsonObjects.add(value);
  }
  
  print('$jsonObjects');
  
  print('Second object: ${jsonObjects[1]}');
}

You can try this at https://dartpad.dev

edited Dec 1, 2020 at 16:58

answered Dec 1, 2020 at 16:30

Teddichiiwa

7896 silver badges9 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

we_mor Over a year ago

Thank you for your answer, I'm getting these data from firebase, so it would be much better if I didn't have to restructure my data, in order to use the solution you recommended.

Teddichiiwa Over a year ago

Ok, in that case, you must make an array of your "key" object and append every key to it, then you are good to go with accessing them by using index :D

we_mor Over a year ago

That's a great idea. If you want, edit your answer above and include this solution too, so I can accept your answer. Thank you very much!

Teddichiiwa Over a year ago

Thank you, I will include it now

Teddichiiwa Over a year ago

I have updated my answer, you can try this solution on Dartpad too :D

we_mor · Accepted Answer · 2025-03-19 15:16:27Z

0

A pretty simple answer to this question is

final Map json = {
    "key1": {"key": [1,2,3]},
    "key2": {"key": [4,5,7]},
    "key3": {"key": [8,9,10]},
  };
  
final firstEntry = json.entries.toList()[1].value;
print(firstEntry);

answered Mar 19 at 15:16

we_mor

5281 gold badge6 silver badges24 bronze badges

Collectives™ on Stack Overflow

Flutter get json data by index

2 Answers 2

5 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

5 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related