Trying to parse JSON data

Question

I'm writing C++ code using curl and JsonCpp (https://github.com/open-source-parsers/jsoncpp). Json::parseFromStream returns the following data:

Funds: [
        {
                "id" : 1,
                "jsonrpc" : "2.0",
                "result" :
                {
                        "availableToBetBalance" : 437.91000000000003,
                        "discountRate" : 4.0,
                        "exposure" : 0.0,
                        "exposureLimit" : -5000.0,
                        "pointsBalance" : 3135,
                        "retainedCommission" : 0.0,
                        "wallet" : "UK"
                }
        }
]

How do I extract availableToBetBalance - I've tried things like:

std::string d = json_data["result.availableToBetBalance"].asString();

and:

std::string d = json_data["result"]["availableToBetBalance"].asString();

The latter throws and exception : in Json::Value::resolveReference(key, end): requires objectValue

Not knowing which library you use, have you tried something like `json_data["result"]["availableToBetBalance"].asString()`? — Some programmer dude, Mar 02 '18 at 12:08
I'm using jsoncpp (https://github.com/open-source-parsers/jsoncpp). — Steve, Mar 02 '18 at 12:18
did you read the [wiki](https://github.com/open-source-parsers/jsoncpp/wiki)? — default, Mar 02 '18 at 12:30
Yes. I Assime it is the _Funds: [_ that I don't know how to handle. — Steve, Mar 02 '18 at 12:37
Not sure about the 'Funds' bit, but the square brackets indicate an array (even though it only contains one element), have you tried something like json_data[0]["result"]["availableToBetBalance"]? — Sean Burton, Mar 02 '18 at 14:21

score 0 · Answer 1 · answered Mar 03 '18 at 15:26

You're ignoring the array layer, signified by the outer [ and ] characters.

In this particular case, the data you're looking for is in the first (and only) element of an array, so:

std::string d = json_data[0]["result"]["availableToBetBalance"].asString();
//                       ^^^

Trying to parse JSON data

1 Answers1