Signature (computer science)

The signature of a function is a way of describing the parameters and parameter types with which a legal call to the function can be made. It contains the name of the function, its parameters and their type, and the return value.

A better title for what is described here is 'Function signature'. Java teaching tends to use the term 'Method signature' but these terms are interchangeable as long as you are clear on the concept. If C users do in fact? instead use the mouthful 'prototype definition' then again this seems to just be a labelling preference.

The notion of a function signature is an important concept for all computer science undergraduates

• Modern Object Orientation techniques make much use of Interfaces which are essentially a template made from function signatures
• C++ teaching must cover the important concept of function overloading which involves first introducing function signatures.

The practice of multiple inheritance requires careful consideration of the function signatures to avoid unpredictable results.

Computer science theory and the teaching of polymorphism in particular makes much use of the concept of function signature.

Roughly equivalent to its prototype definition in the C programming language.

CS, like many sciences, reuses terminology frequently. If you encounter the term 'signature' in an area of CS not concerned with programming then be sure to check your terminology with the published texts to avoid confusion.

External links

• OOP demystified - Run time polymorphism in action
• Barrons AP Computer Science - Chapter - Inheritance and Polymorphism

Other areas of Computer Science where you might encounter the term signature:

• The study of databases might also involve the use of the term 'signature', however, before confusing the two things be sure of the definition at the top of this article.

In the ML family of programming languages, signature is a keyword referring to a construct of the module system that plays the role of an interface.