What is the use/advantage of function overloading?

Question

What is the use/advantage of function overloading?

Answer 1

IMO, the primary benefit is consistency in the naming of methods / functions which logically perform very similar tasks, and differ slightly in by accepting different parameters. This allows the same method name to be reused across multiple implementations.

e.g. The overloads: (Good)

function Person[] FindPersons(string nameOfPerson) { ... } function Person[] FindPersons(date dateOfBirth) { ... } function Person[] FindPersons(int age, string dogsName) { ... } 

Are preferable to 'uniquely named' functions: (Worse)

function Person[] FindPersonsByName(string nameOfPerson) { ... } function Person[] FindPersonsByDOB(date dateOfBirth) { ... } function Person[] FindPersonsByAgeAndDogsName(int age, string dogsName) { ... } 

This way the coder writing a client which calls / consumes these functions can operate at a higher level of conceptual thinking ("I need to find a person") and doesn't need to remember / locate a contrived function name.

With static typing, the compiler will be left to match the applicable overload based on the usage parameters. For dynamic typing, this same match up will happen at run time, possibly resulting in failure if no appropriate match is found.

Answer 2

Very valid question.

You get consistency in naming, but at the cost of ambiguity about exact implementation.

• The real issue is human memory for method names, right? we find it easier to remember names that are commonly used.

• and economy of typing, allowing for shorter method names? fewer different names means (mathematically) that the name itself carries less information.

These two issues shouldn't be any concern, with IDEs that find/guess/insert method names rapidly based on the first few characters, and parameter/return types.

But I do think there is a cost, in preciseness of coding, as well as a benefit.