Lab 4.1: Variables and Functions

Overview

This lab aims to solve more coding challenges that involve creating and manipulating variables, using functions with multiple parameters, and handling conditional logic.

Learning Objectives

By completing this lab, I have demonstrated the ability to:

• Manipulate variables to perform mathematical operations and string manipulation.
• Write and call functions that use parameters and return values.
• Use conditional logic inside functions to create more dynamic behavior.
• Refactor code to improve readability and reusability.

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Tasks Completed

Task 1: Flexible String Manipulation with Functions

• Created a function called formatFullName that takes two parameters: firstName and lastName and returns the full name in the format lastName, firstName.
• Formatted the firstName and lastName so that the first letter of each is always capatilized.
• Added a condition that checks if either the first or last name is missing. If so, there is a returning string saying “Invalid name input.”

Task 2: Mathematical Operations with Multiple Parameters

• Wrote a function called calculateTotalCost that takes three parameters: price, quantity, and taxRate.
• The function calculates the total cost of items, including tax. Use the formula: totalCost = (price * quantity) * (1 + taxRate).
• Checked that price, quantity, and taxRate are all valid numbers. If any are invalid, return a string: “Invalid input.”

Task 3: Functions with Conditional Logic

• Wrote a function called checkEligibility that takes two parameters: age and isEmployed. The function checks if a person is eligible for a program based on the following rules:
• If the person is over 18 and employed, they are eligible.
• If the person is over 18 but unemployed, they are conditionally eligible.
• If the person is 18 or younger, they are not eligible. Returns an appropriate string message for each scenario.

Task 4: Refactoring for Reusability

• Refactored the calculateTotalCost function from Task 2 to include an optional discount parameter.

• If the discount is provided, the function should subtract the discount from the total cost before applying tax.

• If no discount is provided, calculate the total cost as before.

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How to Run This Project

1. Clone the repository or download the .zip file.
2. Navigate to Tasks folders and run index.js file in your local development environment.
3. Change the example usage to test the code response.

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Technologies Used

• JavaScript (ES6)

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File Structure

 variables-and-functions/
├── Task1
├── Task2
├── Task3
├── Task4
└── README.md

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Reflection Questions

1. How did you approach creating more flexible functions with parameters?

I focused on defining clear function signatures that accept parameters, allowing for dynamic behavior based on user input. This approach enhances the reusability of the functions across different scenarios.

2. What challenges did you face while incorporating conditional logic in your functions?

One challenge was ensuring that all edge cases were handled correctly, such as validating inputs and providing appropriate feedback.

3. How does refactoring improve the readability and maintainability of your code? Refactoring helps to simplify complex functions, making them easier to understand and modify in the future.