# Use of NULL vs nullptr in UE4 C++ **URL:** \ **Category:** C++\ **Tags:** unreal-engine, feedback, CPP, question\ **Created:** [March 11, 2014, 1:56am UTC](https://forums.unrealengine.com/t/use-of-null-vs-nullptr-in-ue4-c/275136 "2014-03-11T01:56:01Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![ue4-archive](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ue4-archive](https://forums.unrealengine.com/u/ue4-archive)\ **Post date:** [March 11, 2014, 1:56am UTC](https://forums.unrealengine.com/t/use-of-null-vs-nullptr-in-ue4-c/275136/1 "2014-03-11T01:56:01Z")
Dear Friends at Epic, Expert coder Neil Griffth recently wrote this: > “You should really try to avoid using > NULL if possible and instead use > nullptr. It’s a lot safer if only > because you’re not checking against a > number (zero) - and it’s part of the > C++ language as of C++11 (which is > required by Rocket in any case!).” #My Question I was wondering if NULL in UE4 C++ still uses the actual macro, **or if Epic has done this definition somewhere** : ``` #define NULL nullptr ``` * * * #Summary Anyone with any comments on NULL vs nullptr, feel free to post. I am not taking a stance on this, I am asking for more info 🙂 Though I do want to say, **Thanks Neil for bringing this to my attention**! Rama ---
**Author:** ![ue4-archive](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ue4-archive](https://forums.unrealengine.com/u/ue4-archive)\ **Post date:** [March 11, 2014, 1:56am UTC](https://forums.unrealengine.com/t/use-of-null-vs-nullptr-in-ue4-c/275136/2 "2014-03-11T01:56:02Z")
> Expert coder Neil Griffth recently > wrote this: Yep, he truly is … lucky us 🙂 ---
**Author:** ![ue4-archive](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ue4-archive](https://forums.unrealengine.com/u/ue4-archive)\ **Post date:** [March 11, 2014, 1:56am UTC](https://forums.unrealengine.com/t/use-of-null-vs-nullptr-in-ue4-c/275136/3 "2014-03-11T01:56:02Z")
hee hee! 🙂 ---
**Author:** ![ue4-archive](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ue4-archive](https://forums.unrealengine.com/u/ue4-archive)\ **Post date:** [March 11, 2014, 1:56am UTC](https://forums.unrealengine.com/t/use-of-null-vs-nullptr-in-ue4-c/275136/4 "2014-03-11T01:56:03Z")
To answer your question, I think NULL is a Microsoft thing; IIRC it’s defined in Windows.h, which is probably getting included somewhere along the line. I doubt it’s #defined anywhere. It’s part of C++ now. But yes, nullptr is most definitely preferred IMO 🙂 ---
**Author:** ![ue4-archive](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ue4-archive](https://forums.unrealengine.com/u/ue4-archive)\ **Post date:** [March 11, 2014, 1:56am UTC](https://forums.unrealengine.com/t/use-of-null-vs-nullptr-in-ue4-c/275136/5 "2014-03-11T01:56:03Z")
neat! The .h files of UE4 mostly use NULL, I found about 30 references in the .h to nullptr I’m just curious if Epic has made them internally the same by ``` #define NULL nullptr ``` or not ---
**Author:** ![ue4-archive](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ue4-archive](https://forums.unrealengine.com/u/ue4-archive)\ **Post date:** [March 11, 2014, 1:56am UTC](https://forums.unrealengine.com/t/use-of-null-vs-nullptr-in-ue4-c/275136/6 "2014-03-11T01:56:03Z")
It’s unlikely that they did that - if they did that then it could break code for people who are using NULL as a value. 🙂 ---
**Author:** ![ue4-archive](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ue4-archive](https://forums.unrealengine.com/u/ue4-archive)\ **Post date:** [March 11, 2014, 1:56am UTC](https://forums.unrealengine.com/t/use-of-null-vs-nullptr-in-ue4-c/275136/7 "2014-03-11T01:56:04Z")
Well, thanks again for shedding light on this subject Neil! #❤ ---
**Author:** ![ue4-archive](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ue4-archive](https://forums.unrealengine.com/u/ue4-archive)\ **Post date:** [March 11, 2014, 1:56am UTC](https://forums.unrealengine.com/t/use-of-null-vs-nullptr-in-ue4-c/275136/8 "2014-03-11T01:56:04Z")
Just to clarify, you can check with: int value1 = NULL; int value2 = nullptr; The first compiles, but not the second, meaning NULL is still defined to 0. ---
**Author:** ![ue4-archive](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ue4-archive](https://forums.unrealengine.com/u/ue4-archive)\ **Post date:** [March 11, 2014, 1:56am UTC](https://forums.unrealengine.com/t/use-of-null-vs-nullptr-in-ue4-c/275136/9 "2014-03-11T01:56:04Z")
oooh great insight Andrew! **Thanks Andrew!** That fully answers this thread 🙂 Thanks everyone, for the info! #❤ Rama ---
**Author:** ![anon67567687](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anon67567687](https://forums.unrealengine.com/u/anon67567687)\ **Post date:** [November 9, 2018, 9:02pm UTC](https://forums.unrealengine.com/t/use-of-null-vs-nullptr-in-ue4-c/275136/10 "2018-11-09T21:02:58Z")
Found the answer on the coding standard page : > **[Coding Standard](https://docs.unrealengine.com/5.3/en-US/epic-cplusplus-coding-standard-for-unreal-engine/)** > > Write maintainable code by adhering to established standards and best practices. > nullptr should be used instead of the > C-style NULL macro in all cases. One > exception to this is that nullptr in > C++/CX builds (such as for Xbox One) > is actually the managed null reference > type. It is mostly compatible with > nullptr from native C++ except in its > type and some template instantiation > contexts, and so you should use the > TYPE\_OF\_NULLPTR macro instead of the > more usual decltype(nullptr) for > compatibility. ---
**Author:** ![MBybee](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MBybee](https://forums.unrealengine.com/u/MBybee)\ **Post date:** [September 13, 2020, 12:16am UTC](https://forums.unrealengine.com/t/use-of-null-vs-nullptr-in-ue4-c/275136/11 "2020-09-13T00:16:58Z")
This is an old thread, but I thought I’d mention that as of 4.25.3, the Third Person Template from Epic still uses !=NULL repeatedly in the character CPP If that’s not a good practice, they should _probably_ update their code samples to keep people from misunderstanding it. ---
**Author:** ![Mynkela](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Mynkela](https://forums.unrealengine.com/u/Mynkela)\ **Post date:** [August 14, 2021, 4:02pm UTC](https://forums.unrealengine.com/t/use-of-null-vs-nullptr-in-ue4-c/275136/12 "2021-08-14T16:02:35Z")
_Example:_ ``` class AMyDefaultClass* theDefaultClass; ``` \*\*\*\*//**the class was exist & IsValid(), So class is not NULL** ``` if(theDefaultClass != NULL) UE_LOG(LogTemp, Warning, TEXT("AMyDefaultClass is not NULL")); ``` **//the class IsValid() but you not able to use class data(variable, function(), etc) with public otherwise crash editor, So class was nullptr** ``` if(theDefaultClass == nullptr) UE_LOG(LogTemp, Warning, TEXT("AMyDefaultClass was nullptr")); ```