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C# -> C++ conversion questions

Development Discussion C++ Gameplay Programming
#1

Hey guys :slight_smile:

I’m a Unity programmer of +7 years making the move to Unreal, in other words the transformation from C# to C++
I literally just started today. Nice to meet you! :slight_smile:

Not sure where is the best place to post this but I have some C++ questions of which I couldn’t seem to successfully google and figure out myself.
I have some n00b question for you all, so many apologies in advance.

In the getting started section in the Unreal documents I found this bit of code

" virtual void NotifyActorBeginOverlap(AActor* Other) override;"

Can anyone explain why the final “override;” at the end is needed?

Now in Unity C# with virtual functions you do something like

virtual void Moo() {}

and then later on you would override it like this:-

override void Moo() {}

I find it unusual that you would need to use override and virtual in the same declaration. For me, if you declare a virtual function then it should overridable by default.

Another puzzle I encountered was this line (and similar)

“for (TObjectIterator<UMyClass> It; It; ++It)”

A normal for loop goes something like

for(initialization; condition ; increment/decrement)

The above line is more akin to foreach which I believe it is

In Unity C# this is something like

foreach (UMyClass It in UMyClassList)
{
}

However, I don’t under the syntax. To me

for (TObjectIterator<UMyClass> It; ++It)

seems more correct.

or

for (TObjectIterator<UMyClass> It; MyItList; ++It)

If someone could explain the syntax, I would be incredibly grateful.

Thanks for reading this far :slight_smile:

#2

Hi!

Good link:
https://en.cppreference.com/w/cpp/language/override

You can ignore override specifier if you want.


for (TObjectIterator<UMyClass> It; It; ++It)

initialization: TObjectIterator<UMyClass> It - create iterator by all UMyClass objects
condition: It - means It != nullptr
increment: ++It - means next object

#3

If you want to iterate a list (aka a TArray container) with a C# similar syntax you can do this:


for (auto Object : Objects)

where Objects is a TArray<UObject>