Unreal Engine 5 · Blueprint → C++
Append / Build String in Unreal Engine 5 C++UE Docs
The Blueprint Append node concatenates strings. In Unreal Engine 5 C++ you use the FString operator+ to join strings and FString::Append() to add text to an existing string in place.
Blueprint node & C++ equivalent
FString Result = TEXT("Score: ") + FString::FromInt(Score);
Result.Append(TEXT(" pts"));What does the Append node do?
The Append node joins two or more strings into a single string. In Blueprint you wire string pins together; in C++ the same result comes from concatenating FString values. FString overloads operator+, so TEXT("Score: ") + FString::FromInt(Score) produces a new combined string.
The C++ equivalent
Use operator+ to build a new FString, and call Append() to add more text onto an existing one. In the snippet, FString::FromInt(Score) converts the integer to a string before concatenation, then Result.Append(TEXT(" pts")) modifies Result in place rather than allocating a separate result.
Always wrap string literals in the TEXT() macro so they compile as wide-character TCHAR literals, which is what FString expects.
Common mistakes
Forgetting TEXT() around literals can cause encoding mismatches or compile errors. Also note that operator+ allocates a new string each time, so for many concatenations in a loop prefer Append() or FString::Printf to reduce allocations.
Frequently asked questions
How do you concatenate strings in UE5 C++?+
Use the FString operator+, for example FString A = TEXT("Hello ") + OtherString;. To add text to an existing string in place, call A.Append(TEXT(" world")).
What is the difference between operator+ and Append in FString?+
operator+ returns a new FString, leaving the originals unchanged. Append() modifies the calling string directly, which avoids an extra allocation when you are building one string up.