When without argument in Kotlin - Mini Project: Build & Apply

Using When Without Argument in Kotlin

📖 Scenario: You are building a simple program that checks different conditions about a number and prints messages accordingly.

🎯 Goal: Learn how to use the when expression without an argument to check multiple conditions in Kotlin.

📋 What You'll Learn

Create a variable called number with the value 15

Create a variable called isEven that checks if number is even

Use a when expression without argument to check conditions on number and isEven

Print the correct message based on the conditions

💡 Why This Matters

🌍 Real World

Using <code>when</code> without argument helps you check multiple conditions clearly and cleanly, which is useful in many programs like games, calculators, or decision-making apps.

💼 Career

Understanding <code>when</code> expressions is important for Kotlin developers to write readable and efficient code that handles different cases without complicated if-else chains.

1

Create the number variable

Create a variable called number and set it to 15.

Kotlin

# Create a variable called number and set it to 15
# Your code here

Need a hint?

Use val number = 15 to create the variable.

2

Create the isEven variable

Create a variable called isEven that is true if number is even, otherwise false. Use number % 2 == 0.

Kotlin

val number = 15
# Create a variable called isEven that checks if number is even
# Your code here

Need a hint?

Use the modulus operator % to check if the number is even.

3

Use when without argument to check conditions

Write a when expression without argument that checks these conditions in order:
1. If number is less than 10, print "Number is less than 10".
2. If isEven is true, print "Number is even".
3. Otherwise, print "Number is odd and 10 or more".
Use when { ... } syntax with conditions as branches.

Kotlin

val number = 15
val isEven = number % 2 == 0
# Use when without argument to check conditions and print messages
# Your code here

Need a hint?

Use when { condition -> action } to check each condition.

4

Print the result

Run the program to print the correct message based on the when expression.

Kotlin

val number = 15
val isEven = number % 2 == 0
when {
    number  println("Number is less than 10")
    isEven -> println("Number is even")
    else -> println("Number is odd and 10 or more")
}
# Run the program to see the output

Need a hint?

The output should be Number is odd and 10 or more because 15 is odd and greater than 10.