Working with Assets in Unreal Engine

How to import various kind of assets to Unreal Engine with C++?

An Asset is any piece of content in an Unreal Engine project.

Check if a file exists on a disk

#include "HAL/PlatformFileManager.h" // Core
 * Check whether a file exists on the disk
 * @param FilePath	The path of targeted file, e.g. "C:/Temp/MyFile.txt"
 * @param OutInfoMsg    Help for action's result
 * @return The string content of the file
static bool DoesFileExist(FString FilePath, FString& OutInfoMsg);
bool UExampleClass::DoesFileExist(FString FilePath, FString &OutInfoMsg)
    bool bFileExist = FPlatformFileManager::Get().GetPlatformFile().FileExists(*FilePath);
    if(!bFileExist) OutInfoMsg = FString::Printf(TEXT("Error: No File found at: '%s'"), *FilePath);
    return bFileExist;