I am trying to use TryGetValue on a Dictionary as usual, like this code below:
Response.Context.Skills[MAIN_SKILL].UserDefined.TryGetValue("action", out var actionObj)
My problem is the dictionary itself might be null. I could simply use a "?." before UserDefined but then I receive the error:
"cannot implicitly convert type 'bool?' to 'bool'"
What is the best way I can handle this situation? Do I have to check if UserDefined is null before using TryGetValue? Because if I had to use Response.Context.Skills[MAIN_SKILL].UserDefined twice my code could look a little messy:
if (watsonResponse.Context.Skills[MAIN_SKILL].UserDefined != null &&
watsonResponse.Context.Skills[MAIN_SKILL].UserDefined.TryGetValue("action", out var actionObj))
{
var actionName = (string)actionObj;
}
Add a null check (?? operator) after the bool? expression:
var dictionary = watsonResponse.Context.Skills[MAIN_SKILL].UserDefined;
if (dictionary?.TryGetValue("action", out var actionObj)??false)
{
var actionName = (string)actionObj;
}
Another option is to compare to true.
It looks slightly weird, but it works with three-valued logic and says: is this value true but not false or null
if (watsonResponse.Context.Skills[MAIN_SKILL]
.UserDefined?.TryGetValue("action", out var actionObj) == true)
{
var actionName = (string)actionObj;
}
You can do the opposite logic with != true: is this value not true, so either false or null
if (watsonResponse.Context.Skills[MAIN_SKILL]
.UserDefined?.TryGetValue("action", out var actionObj) != true)
{
var actionName = (string)actionObj;
}