Dealing with arrays

[mtangoo]

I have json like below. Now I want to check if given file is in array and open it. I tried get() but it does not work. this code crashes

         std::string pluginNameStr = "DOESNOTEXIST.json";
            Json::Value p = m_jsonPlugins.get(pluginNameStr, 0);
            if(!p.empty())
            {
                ret = p.asCString();
            }

{
    "plugins" : [ "/home/stefano/plugins/prefs/Git.json" ]
}

What is right way of dealing with arrays?

[cdunn2001]

Not sure I understand, but the whole API is here:

• http://open-source-parsers.github.io/jsoncpp-docs/doxygen/index.html

[mtangoo]

Sorry if I didn't explain it clearly
I have json with array in it. I pull the array object into Value object. Now I want to check in that array of strings if certain string exists and if it does get the value

Jsoncpp is wonderful only lacking few things like this one :)

[mtangoo]

And I. Already read the docs many times

[cdunn2001]

Here is the most useful page.

• isArray() tells whether a Value is from a JSON array.
• size(), get(ArrayIndex, Value) (or operator[](ArrayIndex)), and isValidIndex() can be used to look up items in the array. (I'd avoid using only operator[]() or get() since they return a valid Value even when there is no element, but they're fine if you have already checked the size.)

If someone made a really great wrapper of useful functions, we'd be happy to link it from our docs.

[MartinBonner]

If you can use C++11, then something like the following should do:

bool isFileInPlugins( const Value& pluginsArray, const std::string& file)
{
    if (!pluginsArray.isArray()
        return false;

    for (const auto& el : pluginsArray)
    {
        if (el.isString() && el.asString() == file)
            return true;
    }
    return false;
}

If you can't use C++11, then you'll have to write the for loop with iterators and begin and end yourself.

[MartinBonner]

Ooh. But if you are running on Windows, beware that you need to consider case insensitive comparisons for filenames.