Week 4 - Data structures and loops

Arrays

Loops

Objects

Package managers

Tools (IDE code editing)

Style - Autoformatting

Practice

Assignment

Back to core program

Week 4 Assignment - Personal Finance Tracker

Build a command-line personal finance tracker that manages income and expenses with proper tooling.

Project Requirements

Setup & Configuration

• Initialize npm project with proper package.json
• Install dependency: [email protected]
• Create .gitignore for node_modules/
• Set up Prettier with .prettierrc
• Use proper project structure

Core Functionality

1. Data Structure (Objects & Arrays)

Create a transactions array containing at least 5 transaction objects:

const transactions = [
  {
    id: 1,
    type: 'income',
    category: 'salary',
    amount: 3000,
    description: 'Monthly salary',
    date: '2025-01-15'
  },
  // ... more transactions
];

Each transaction must have: id, type (income/expense), category, amount, description, date.

2. Required Functions

Implement these functions using appropriate loops and array methods:

• addTransaction(transaction) - Add new transaction to array
• getTotalIncome() - Sum all income using a loop
• getTotalExpenses() - Sum all expenses using a loop
• getBalance() - Calculate total income minus expenses
• getTransactionsByCategory(category) - Filter transactions (use loop + push or indexOf/includes)
• getLargestExpense() - Find highest expense amount
• printAllTransactions() - Display all transactions with formatting

3. Display Requirements (Chalk)

Use chalk to color-code output:

• Income amounts in green
• Expense amounts in red
• Balance in cyan (or red if negative)
• Category names in yellow
• Totals/summaries in bold

4. Summary Report

Create a printSummary() function that displays:

• Total income
• Total expenses
• Current balance
• Number of transactions
• Largest expense with description

5. Code Quality

• Use descriptive variable names
• Add comments for complex logic
• Use appropriate loop types (for, for...of, while)
• Demonstrate object destructuring in at least one function
• Use spread operator when adding transactions
• Format entire codebase with Prettier before submission

Example Output

💰 PERSONAL FINANCE TRACKER 💰

All Transactions:
1. [INCOME] Salary - €3000 (salary)
2. [EXPENSE] Rent - €1200 (housing)
3. [EXPENSE] Groceries - €300 (food)
4. [INCOME] Freelance - €500 (side-income)
5. [EXPENSE] Utilities - €150 (bills)

📊 FINANCIAL SUMMARY 📊
Total Income: €3500
Total Expenses: €1650
Current Balance: €1850

Largest Expense: Rent (€1200)
Total Transactions: 5

Bonus Challenges

• Search transactions by date range using slice
• Group transactions by month using nested objects
• Calculate average expense per category
• Add ability to remove transactions by id
• Create a function that finds consecutive expensive months (use while loop)
• Use multi-line commenting to explain your most complex function

Submission

TBD

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