Software Development Life Cycle (SDLC)

• SDLC consists of several phases: requirements gathering, design, implementation, testing, deployment, and maintenance.
• Example: Let's consider a web application development project. The SDLC phases would involve gathering user requirements, creating wireframes or prototypes, implementing the application using a programming language and framework, testing the application's functionality, deploying it to a server or cloud platform, and maintaining it by fixing bugs and adding new features.

Agile Methodology

• Agile emphasizes flexibility, collaboration, and incremental development.
• Example: In an agile project, a product backlog is created with user stories representing features or requirements. The development team works on a small subset of user stories in each iteration (sprint), delivering working software at the end of each sprint. The product owner and team collaborate regularly to prioritize and refine the backlog based on feedback.

Waterfall Methodology

• The Waterfall model follows a sequential approach, with each phase completed before moving to the next.
• Example: In a waterfall project, the requirements phase would be completed first, followed by design, implementation, testing, deployment, and maintenance. Each phase is signed off before the next one begins.

Version Control

• Version control systems, such as Git, allow tracking changes to source code, enabling collaboration among developers.
• Example: With Git, developers can create a new branch to work on a specific feature or bug fix. They commit changes to their branch, and when ready, merge the branch back into the main branch (usually called 'master' or 'main').

# Git commands
git branch feature-branch # Create a new branch
git checkout feature-branch # Switch to the new branch
git add . # Stage changes
git commit -m "Implement feature" # Commit changes
git checkout main # Switch back to the main branch
git merge feature-branch # Merge the changes`

Code Documentation

• Documentation is crucial for code comprehension, maintenance, and collaboration among developers.
• Example: Adding comments to code to explain its functionality or intent.

# Python example
def calculate_square(number): """ Calculates the square of a number. Args: number (int): The number to be squared. Returns: int: The square of the number. """ return number * number

Testing

• Testing ensures software quality and verifies that it meets requirements.
• Example: Writing unit tests to verify the functionality of individual functions.