JsonCpp: Undefined reference to `Json::Value::operator[](int) const'

Question

i'm trying to use JsonCpp with this sample code

string json_example = "{\"array\":[\"item1\", \"item2\"], \"not an array\":\"asdf\"}";


    // Let's parse it
    Json::Value root;
    Json::Reader reader;


    //Parsing of something. In example do parsing of json_example string.
    bool parsedSuccess = reader.parse(json_example, root, false);

    if (!parsedSuccess) {
        // report to the user the failure and their locations in the document.
        cout  << "Failed to parse JSON" << endl << reader.getFormatedErrorMessages() << endl;
        return 1;
    }

    // Let's extract the array that is contained inside the root object
    const Json::Value array = root["array"];

    // And print its values
    for (int index = 0; index < array.size(); ++index) {   // Iterates over the sequence elements.
        cout << "Element " << index << " in array: " << array[index].asString() << endl;
    }

    // Lets extract the not array element contained in the root object and print its value
    cout << "Not an array: " << root["not an array"] << endl;

    // If we want to print JSON is as easy as doing:
    cout << "Json Example pretty print: " << endl << root.toStyledString() << endl;

    return 0;

but i've received this error on this "..array[index].asString..."

Undefined reference to `Json::Value::operator[](int) const'

can anyone help me?!tnx so much

The code above compiles for me. Are you getting the link error ? Something like LNK2019 in Visual Studio ? Add the reference to the precompiled jsoncpp library to your project. — Viktor Latypov
– Viktor Latypov, Commented Sep 14, 2012 at 18:40

Marcofe · Accepted Answer · 2012-09-15 14:42:40Z

1

Tnx for your answer... So the solution is changing this

 for (int index = 0; index < array.size(); ++index) {   // Iterates over the sequence elements.
    cout << "Element " << index << " in array: " << array[index].asString() << endl;
}

with

 for (unsigned int index = 0; index < array.size(); ++index) {   // Iterates over the sequence elements.
    cout << "Element " << index << " in array: " << array[index].asString() << endl;
}

bye

answered Sep 15, 2012 at 14:42

Marcofe

411 gold badge1 silver badge4 bronze badges

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

1 Comment

cdunn2001 Over a year ago

This is a quirk of an unfortunate API decision. Sorry.

Vladyslav Nikolaiev · Accepted Answer · 2015-10-10 13:32:41Z

0

I think you didn't included jsoncpp.cpp file, which describes your json.h library file. U have to generate it using Pythot with command python amalgamate.py and then include it into your project

answered Oct 10, 2015 at 13:32

Vladyslav Nikolaiev

2,0593 gold badges24 silver badges44 bronze badges

Collectives™ on Stack Overflow

JsonCpp: Undefined reference to `Json::Value::operator[](int) const'

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related