Can Go have optional parameters? Or can I just define two functions with the same name and a different number of arguments?
Go does not have optional parameters nor does it support method overloading:
Method dispatch is simplified if it doesn’t need to do type matching as well. Experience with other languages told us that having a variety of methods with the same name but different signatures was occasionally useful but that it could also be confusing and fragile in practice. Matching only by name and requiring consistency in the types was a major simplifying decision in Go’s type system.