Invoking is_array() function creates "null" value

[drewpts]

Hello.

 if (j[SUBPR_DESCR].is_array()) {
                if (j[SUBPR_DESCR].at(0).is_string() == false)
                    return json::parse(error_code + "Wrong values type of subprojects key!\"}");
            } else if (!j[SUBPR_DESCR].is_null() && !j[SUBPR_DESCR].is_array()) {
                return json::parse(error_code + "Corrupted or absent subprojects key!\"}");
            }

After invoking such function on json object data with key SUBPR_DESCR appearing with value "none".

[offtop] Lol, horrible char * to string casting at the bottom of image 🐹 [/offtop]

[drewpts]

I just faced similar behaviour with method is_null(): if no value in object j under "subprojects" key invoking j["subprojects"].is_null() creates such value (see screen):

Thank you for you attention!:)

[nlohmann]

What you try to do is to find out whether an object stores a value for a key. For that, you could try j.count("subprojects") == 0.

However, j["subprojects"] has a different semantics: If a key subprojects is stored in j, it returns a reference to that object. But if it does not, it creates a null value for that key. While this may make little sense when combined with is_null(), it helps to create objects easily, for instance j["foo]["bar"] = 1.