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.

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Observer Pattern

A design pattern where an object (subject) maintains a list of dependents (observers) that are notified automatically of state changes.

An efficient search algorithm that finds a target value in a sorted array by repeatedly dividing the search interval in half.

SOLID Principles

Five design principles for writing maintainable, flexible object-oriented code: Single Responsibility, Open-Closed, Liskov Substitution, Interface Segregation, and Dependency Inversion.

A linear data structure where elements are stored in nodes, each containing data and a pointer to the next node in the sequence.

The smallest unit of execution within a process, allowing concurrent operations to run within a single program.

Code that is easy to read, understand, and maintain — following consistent conventions, meaningful naming, and single-responsibility functions.

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