Collection size and emptiness checks in Kotlin - Mini Project: Build & Apply

Collection size and emptiness checks

📖 Scenario: You are managing a small library database. You want to keep track of books available in different genres. You will create a collection of books, check how many books are in the collection, and find out if the collection is empty or not.

🎯 Goal: Build a Kotlin program that creates a collection of books, sets a threshold for minimum books, checks the collection size, and verifies if the collection is empty.

📋 What You'll Learn

Create a list of books with exact titles

Create a variable for minimum book count threshold

Check the size of the book list using size

Check if the book list is empty using isEmpty()

Use exact variable names as instructed

💡 Why This Matters

🌍 Real World

Managing collections of items like books, products, or users is common in apps and databases. Checking size and emptiness helps control flow and decisions.

💼 Career

Understanding collection properties like size and emptiness is essential for database queries, data validation, and application logic in software development.

1

Create a list of books

Create a list called books with these exact book titles: "Kotlin Basics", "Advanced Kotlin", "Database Essentials".

Kotlin

# Create a list called books with the exact titles
# Your code here

Need a hint?

Use listOf() to create a list with the exact book titles.

2

Set minimum book count threshold

Create an integer variable called minBooks and set it to 3.

Kotlin

val books = listOf("Kotlin Basics", "Advanced Kotlin", "Database Essentials")
# Create an integer variable minBooks and set it to 3
# Your code here

Need a hint?

Use val to create a constant integer variable.

3

Check the size of the book list

Create an integer variable called bookCount and set it to the size of the books list using books.size.

Kotlin

val books = listOf("Kotlin Basics", "Advanced Kotlin", "Database Essentials")
val minBooks = 3
# Create an integer variable bookCount and set it to books.size
# Your code here

Need a hint?

Use the size property of the list to get the number of items.

4

Check if the book list is empty

Create a boolean variable called isEmpty and set it to books.isEmpty() to check if the list is empty.

Kotlin

val books = listOf("Kotlin Basics", "Advanced Kotlin", "Database Essentials")
val minBooks = 3
val bookCount = books.size
# Create a boolean variable isEmpty and set it to books.isEmpty()
# Your code here

Need a hint?

Use the isEmpty() function to check if the list has no items.