Programming Concepts Beginner

What is Unit Testing?

Testing individual components or functions of a program in isolation to verify they work correctly.

Unit tests verify that individual functions, methods, or classes produce correct output for given inputs. They run fast, test in isolation (using mocks/stubs for dependencies), and provide immediate feedback when code breaks.

Popular frameworks include pytest (Python), JUnit (Java), Jest (JavaScript), and PHPUnit (PHP). Test-Driven Development (TDD) writes tests before implementation. Good tests are independent, repeatable, and cover edge cases.

Learn More About This Topic

Mastering Python Object-Oriented Programming

Related reading

Mastering Python Object-Oriented Programming - 2nd Edition (2026)

Related reading

Clean Python Code: Best Practices for Writing Maintainable and Readable Python

Related reading

Related Terms

A data structure that follows Last-In-First-Out (LIFO) ordering, where elements are added and removed from the same end (top).

A function that captures and retains access to variables from its enclosing scope, even after that scope has finished executing.

Twelve-Factor App

A methodology of twelve best practices for building modern, scalable, maintainable software-as-a-service applications.

A data structure that follows First-In-First-Out (FIFO) ordering, where elements are added at the rear and removed from the front.

Two memory regions: the stack stores function call data with automatic cleanup, while the heap stores dynamically allocated objects.

Functional Programming

A programming paradigm that treats computation as the evaluation of mathematical functions, avoiding state changes and mutable data.

View All Programming Concepts Terms →