Sample Usage of JsonDocument and JsonElement

json-document.cs

static double ParseJson()
{
    const string json = " [ { \"name\": \"John\" }, [ \"425-000-1212\", 15 ], { \"grades\": [ 90, 80, 100, 75 ] } ]";

    double average = -1;

    using (JsonDocument doc = JsonDocument.Parse(json))
    {
        JsonElement root = doc.RootElement;
        JsonElement info = root[1];

        string phoneNumber = info[0].GetString();
        int age = info[1].GetInt32();

        JsonElement grades = root[2].GetProperty("grades");

        double sum = 0;
        foreach (JsonElement grade in grades.EnumerateArray())
        {
            sum += grade.GetInt32();
        }

        int numberOfCourses = grades.GetArrayLength();
        average = sum / numberOfCourses;
    }

    return average;
}

This is a very helpful example. Thanks.