Is there a way to get an element from a JSON without throwing an exception on failure?

[d223chen]

For example, say j is an nlohmann::json object. I want to try to get a member called "raw" using the following code, but without throwing an exception if it fails -- exceptions seem to be a time bottleneck in my application.

        p.raw = j.at("raw").get<int>();

Is it possible?

[gregmarr]

It depends on whether you want to know if it's there or not, or if you want to get a default value if it's not. If you want to know, use find() first. If you don't care, use value() which takes a default value.

[nlohmann]

I doubt that exceptions are really a time bottleneck, but you could use:

if (j.find("raw") != j.end() and j.is_number_integer())
{
  p.raw = j["raw"];
}

[d223chen]

Changing the code to this:

      p.raw = j.value("raw",0);

seems to have fixed the problem. Before, the code was taking around 12milliseconds to run when the element wasn't available. Now it takes about 6 microseconds even if the element isn't available. Thanks!