Flutter - Remove escape sequence in dart - dart

Question

To decode API response string to JSON, json.decode() works fine.
This will parse a JSON string similar to
{ "Response" : {"Responsecode" : "1" , "Response" : "Success"}}
But in my case, the response comes in the serialized form like:
{\"Response\" : {\"Responsecode\" : \"0\" , \"Response\" : \"Success\"}}
json.decode() won’t work.
In Java, I used StringEscapeUtils.unescapeJson() for the same problem.
I searched for Dart but couldn’t find how to unescape characters in a string.
Edit:
Suppose, the value of key data is abc"de
So, its corresponding JSON would be {"data":"abc\"de"}
And hence during serialization, this json string is escaped to give {\"data\":\"abc\\\"de\"} as the response, which is sent by the API.
So, my intention is to remove the escape sequences, so that I can get the string {"data":"abc\"de"}, which would later be decoded using json.decode(). Removing the escape sequences was done using StringEscapeUtils.unescapeJson() in java.

Answer 1

json.decode can decode single strings too, so you should be able to just call it twice. The first time it'll return you a string (where the escape characters have been decoded) and the second time it'll decode that string into the map:
import 'dart:convert';
void main() {
var a = r'''"{\"Response\" : {\"Responsecode\" : \"0\" , \"Response\" : \"Success\"}}"''';
var b = json.decode(json.decode(a));
print(b['Response']['Responsecode']); // 0
print(b['Response']['Response']); // Success
}