Project design
- Kotlin course
- Expert
- Lesson 43/47
- 6 min
Design the skeleton of the expert final mini app.
Project design
In this five-lesson expert final you will build the Expert Notes mini app. Each lesson adds one piece; in the final lesson KMP, KSP and Compose merge.
The first lesson sets up the skeleton: object App and fun run(): String. This object is the root of the whole app; in later lessons you will add shared data, code generation and UI around it. main just calls App.run() and prints the result.
The App object skeleton
The first lesson defines an object named App. In Kotlin object declares a singleton; you access it directly through its name.
Example skeleton: object App { fun run(): String = "Expert Notes" }. This object is called as App.run(). Methods inside an object need no instance; they are called directly through the object name. In later lessons shared data, code generation and UI will be added around this object.
Practice Define the App object
Define object App. Add fun run(): String = "Expert Notes". In main, write println(App.run()).
Starter code
// Define the App object
// run method returns "Expert Notes"
fun main() {
// call the run method and print the result
}Sample solution
object App {
fun run(): String = "Expert Notes"
}
fun main() {
println(App.run())
}Expected output
Expert Notes
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What does the first lesson set up?
The first lesson defines the root object.- App skeleton Correct answer
- Compose UI
- KSP processor
- iOS framework
Explanation: The first lesson sets up the App object skeleton.
2 Complete the App definition
object App { fun ____(): String { return "Expert Notes" } }object App { fun run(): String { return "Expert Notes" } }Explanation: object App { fun run() } declares the singleton root.
3 Match the App skeleton parts
| Term | Meaning |
|---|---|
object App |
Singleton root |
fun run |
Starter |
Expert Notes |
App name |
main |
Entry point |