Guide to Test-Driven Development (TDD)

What is Test-Driven Development (TDD)?
TDD is an Agile software development methodology used to avoid unexpected problems or errors in code. Developers execute this process by writing a test before coding, ensuring the code function according to the test results. The primary steps or elements in TDD involve writing a test, producing minimum code to pass it and then refactoring it.

Why is TDD Important?
TDD is important because it ensures software quality, reduces the possibility of bugs, facilitates the maintenance and refactoring of code and improves software design. It also reduces development time because fewer bugs mean less time is spent on bug fixing and maintenance.

How does TDD work?
TDD works in cycles and includes three primary steps: write a test, write the code, and then refactor the code. The cycle begins by writing a test for a small bit of functionality. The developer then works on creating code to pass the test. Once the code passes the test, the developer refactors it to improve its structure or design. This cycle is repeated for each new functionality piece.

Exam Tips: Answering Questions on TDD:
1. Understand Core Principles: Make sure you understand the core principles and steps involved in TDD.
2. Real life scenarios: Real life situations can be of great help in understanding the concepts properly.
3. Know the Advantages: It's crucial to understand why TDD is used and the benefits it brings to software development.
4. Practice: Knowing how TDD works theoretically is important, but the ability to apply TDD principles practically also matters.
5. Link it with Agile and Scrum: Understanding the connection between TDD, Scrum and Agile methodologies can help in proper context when asked related queries.