\n gives error when parsing json in flutter

Question

I have a json array like this:

[
{
"variable1":"example",
"variable2": "example1\nexample2\nexample3"
},
{
"variable1":"exampleLast\n",
"variable2": "example1\nexample2\nexample3"
}
]

I am trying to parse this json a List in Flutter.

List posts = json.decode(response.data);

When I tried using 'dart:convert' it gives error FormatException... Control character in string (at line...).

I found this issue on Github but I can not find solution.
https://github.com/dart-lang/convert/issues/10

Try using Gson Gson gson = new Gson(); Categoty _cate = gson.fromJson(jsonresponse, Categoty.class); — Developer, Apr 19 '19 at 06:28
This issue about Flutter not Java. There is no Gson library in flutter. — Enis Erkaya, Apr 19 '19 at 06:31
Hey, @EnisErkaya if you find my answer correct please mark it as correct. so other can use verified answer. — Arjun Vyas, Nov 18 '21 at 06:38

score 2 · Answer 1 · answered Apr 19 '19 at 06:43

2

You just need to replace single slash to double slash and everything goes fine.

String replaced = string.replaceAll(r'\', r'\\');

answered Apr 19 '19 at 06:43

Arjun Vyas

390
3
13

Arbaz Alam · Answer 2 · 2021-07-15T06:08:35.543

2

Just replace the single backslash(\n) with double backslash(\\n) in your code:

[{
    "variable1": "example",
    "variable2": "example1\\nexample2\\nexample3"
},
{
    "variable1": "exampleLast\\n",
    "variable2": "example1\\nexample2\\nexample3"
}]

You need to escape the \ in your string (turning it into a double-), otherwise it will become a newline in the JSON source, not the JSON data.

edited Jul 15 '21 at 06:08

answered Apr 19 '19 at 07:30

Arbaz Alam

1,102
14
23

ramzieus · Answer 3 · 2020-06-10T09:43:36.907

1

And you can replace it like this

String replaced = string.replaceAll('\n', '\\n');

also check this response

edited Jun 10 '20 at 09:43

answered Jun 10 '20 at 09:20

ramzieus

115
10

score 0 · Answer 4 · answered Sep 21 '21 at 13:10

Previous answers didn't help me. In the mentioned Github thread there is a good solution: add r to make compiler think that there is no special characters in the line.

final jsonContent = r'''{ "pageNumber": 0, "pageCount": 0, "transactionId": "126cf723-1d57-4f49-8fb2-072b7c23ec1e", "entries": [ { "content": "{\"resourceType\":\"Bundle\",\"id\":\"DRiefcase_2021-03-15__ManjoorKapoor_Pres-13116\",\"meta\":{\"versionId\":\"1\",\"lastUpdated\":\"2021-01-20T04:51:59.1497479Z\",\"profile\":[\"https:\\/\\/nrces.in\\/ndhm\\/fhir\\/r4\\/StructureDefinition\\/DocumentBundle\"]}}}]}''';

\n gives error when parsing json in flutter

4 Answers4