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c++jsonjsoncpp

Create empty json array with jsoncpp

I have the following code:

void MyClass::myMethod(Json::Value& jsonValue_ref)
{
    for (int i = 0; i <= m_stringList.size(); i++)
    {
        if (m_boolMarkerList[i])
        {
            jsonValue_ref.append(stringList[i]);
        }
    }
}

void MyClass::myOuterMethod()
{
    Json::Value jsonRoot;
    Json::Value jsonValue;
    
    myMethod(jsonValue);

    jsonRoot["somevalue"] = jsonValue;
    Json::StyledWriter writer;
    std::string out_string = writer.write(jsonRoot);
}

If all markers in m_boolMarkerList are false, the out_string is { "somevalue" : null }, but I want it to be an empty array: { "somevalue" : [ ] }

Does anybody know how to achieve this?

Thank you very much!

Solution

  • Here are two ways you can do it:

    jsonRootValue["emptyArray"] = Json::Value(Json::arrayValue);
// or 
jsonRootValue["emptyArray"] = Json::arrayValue;