UPARAM(ref)

UPARAM(ref) is a macro used in Unreal Engine with C++. It is typically used to pass parameters by reference in Unreal Engine function declarations. Let's go through each step:

1. UPARAM: This is a macro provided by Unreal Engine. It is used to annotate function parameters and modify how they are treated by the engine.

2. (ref): The (ref) part of the macro indicates that the parameter should be passed by reference. When a parameter is passed by reference, any changes made to the parameter within the function will be reflected in the original variable that was passed in.

By using UPARAM(ref), you are instructing Unreal Engine to treat the parameter as a reference parameter, allowing you to modify the original value of the parameter from within the function. This can be useful when you want to modify the value of a variable passed into a function and have those changes persist outside of the function scope.