Polymorphism Across 9 Languages: From Overloading to Generics

Polymorphism is a core concept that reduces code volume by enabling reuse across various data types and objects. Overloading is a feature that allows the same function name to accept different input and output types; it is supported in C++, but in C, function names must be distinguished. Go and Rust do not support overloading, considering its risks.

Interface constraints differ by language, but Java and C# have recently made it possible to include implementations in interface methods. Scala and Rust allow more intuitive handling of sum type data through complete pattern matching.

Generics allow variable types to be used when declaring functions or types, securing type safety in data structures and other contexts. Java's ArrayList is a representative example.