Clear All

Part of the Fundamentals section of Coddy's Kotlin journey. Lesson 89 of 93.

Challenge

Medium

In the previous lesson, you implemented the "Total and Average" functionality. Now, implement the "Clear All" functionality for option 4.

Modify your program to handle option 4:

Clear all expenses from the expenses list
Print All expenses cleared!

All other options should continue working as before:

Option 1: Add expense
Option 2: View all expenses
Option 3: Total and average
Option 5: Print Goodbye! and exit
Invalid options: Print Invalid option

Input format:

Menu choices and expense amounts as strings.

Output format:

The menu, followed by the appropriate response for each action.

Example:

If the inputs are 1, 50.0, 1, 25.0, 2, 4, 2, and 5, the output should be:

--- Expense Tracker ---
1. Add Expense
2. View All Expenses
3. Total and Average
4. Clear All
5. Exit
Choose an option:
Enter expense amount:
Expense added!
--- Expense Tracker ---
1. Add Expense
2. View All Expenses
3. Total and Average
4. Clear All
5. Exit
Choose an option:
Enter expense amount:
Expense added!
--- Expense Tracker ---
1. Add Expense
2. View All Expenses
3. Total and Average
4. Clear All
5. Exit
Choose an option:
Your expenses:
- $50.0
- $25.0
--- Expense Tracker ---
1. Add Expense
2. View All Expenses
3. Total and Average
4. Clear All
5. Exit
Choose an option:
All expenses cleared!
--- Expense Tracker ---
1. Add Expense
2. View All Expenses
3. Total and Average
4. Clear All
5. Exit
Choose an option:
No expenses recorded.
--- Expense Tracker ---
1. Add Expense
2. View All Expenses
3. Total and Average
4. Clear All
5. Exit
Choose an option:
Goodbye!

Hint: Use the clear() method on your mutable list to remove all elements.

Try it yourself

fun main() {
    val expenses = mutableListOf<Double>()
    
    while (true) {
        println("--- Expense Tracker ---")
        println("1. Add Expense")
        println("2. View All Expenses")
        println("3. Total and Average")
        println("4. Clear All")
        println("5. Exit")
        println("Choose an option:")
        
        val choice = readLine()
        
        if (choice == "1") {
            println("Enter expense amount:")
            val amount = readLine()!!.toDouble()
            expenses.add(amount)
            println("Expense added!")
        } else if (choice == "2") {
            if (expenses.isEmpty()) {
                println("No expenses recorded.")
            } else {
                println("Your expenses:")
                for (expense in expenses) {
                    println("- \$$expense")
                }
            }
        } else if (choice == "3") {
            if (expenses.isEmpty()) {
                println("No expenses recorded.")
            } else {
                val total = expenses.sum()
                val average = total / expenses.size
                println("Total: \$$total")
                println("Average: \$$average")
            }
        } else if (choice == "5") {
            println("Goodbye!")
            break
        } else {
            println("Invalid option")
        }
    }
}

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