Local functions (nested functions) in Kotlin - Mini Project: Build & Apply

Using Local Functions in Kotlin

📖 Scenario: You are creating a simple program to calculate the total price of items in a shopping cart. To keep your code clean, you will use a local function inside your main function.

🎯 Goal: Build a Kotlin program that uses a local function inside main to calculate the total price of items in a shopping cart.

📋 What You'll Learn

Create a list called prices with exact values: 10, 20, 30

Create a variable called total and set it to 0

Create a local function called addPrice inside main that adds a price to total

Use a for loop to call addPrice for each price in prices

Print the value of total

💡 Why This Matters

🌍 Real World

Local functions are useful when you want to break down a task into smaller steps inside a function without making those steps visible outside. This helps keep your code clean and easier to maintain.

💼 Career

Understanding local functions is important for writing clear and efficient Kotlin code, which is valuable in Android app development and other Kotlin-based projects.

1

Create the list of prices

Create a list called prices with the exact values 10, 20, and 30 inside the main function.

Kotlin

fun main() {
    // Create a list called prices with 10, 20, 30
    // Your code here
}

Need a hint?

Use val prices = listOf(10, 20, 30) to create the list.

2

Create the total variable

Inside the main function, create a variable called total and set it to 0.

Kotlin

fun main() {
    val prices = listOf(10, 20, 30)
    // Create a variable called total and set it to 0
    // Your code here
}

Need a hint?

Use var total = 0 to create a variable that can change.

3

Create the local function and loop

Inside the main function, create a local function called addPrice that takes an Int parameter called price and adds it to total. Then use a for loop with variable price to call addPrice(price) for each price in prices.

Kotlin

fun main() {
    val prices = listOf(10, 20, 30)
    var total = 0
    // Create a local function addPrice(price: Int) that adds price to total
    // Use a for loop to call addPrice(price) for each price in prices
    // Your code here
}

Need a hint?

Define fun addPrice(price: Int) inside main. Use total += price inside it. Then loop with for (price in prices) and call addPrice(price).

4

Print the total

Add a println statement inside main to print the value of total.

Kotlin

fun main() {
    val prices = listOf(10, 20, 30)
    var total = 0
    fun addPrice(price: Int) {
        total += price
    }
    for (price in prices) {
        addPrice(price)
    }
    // Print the total
    // Your code here
}

Need a hint?

Use println(total) to show the total price.