Inline functions and performance in Kotlin - Mini Project: Build & Apply

Inline functions and performance

📖 Scenario: You are building a small Kotlin program to understand how inline functions can improve performance by avoiding extra function calls.

🎯 Goal: Create a Kotlin program that uses an inline function to calculate the sum of two numbers and compare it with a normal function call.

📋 What You'll Learn

Create a normal function called add that takes two Int parameters and returns their sum.

Create an inline function called inlineAdd that takes two Int parameters and returns their sum.

Call both functions with the numbers 10 and 20 and store their results in variables.

Print the results of both function calls.

💡 Why This Matters

🌍 Real World

Inline functions are used in Kotlin to optimize performance, especially when passing lambda functions. This helps apps run faster and use less memory.

💼 Career

Understanding inline functions is important for Kotlin developers working on Android apps or backend services to write efficient and performant code.

1

Create a normal function to add two numbers

Write a normal function called add that takes two Int parameters named a and b and returns their sum.

Kotlin

# Your code here
// Write the normal add function

Need a hint?

Use the fun keyword to create a function named add. It should take two Int parameters and return their sum.

2

Create an inline function to add two numbers

Add an inline function called inlineAdd that takes two Int parameters named a and b and returns their sum.

Kotlin

fun add(a: Int, b: Int): Int {
    return a + b
}

// Your code here
// Write the inlineAdd function

Need a hint?

Use the inline keyword before fun to create an inline function named inlineAdd.

3

Call both functions and store results

Call the add function with arguments 10 and 20 and store the result in a variable called normalResult. Then call the inlineAdd function with the same arguments and store the result in a variable called inlineResult.

Kotlin

fun add(a: Int, b: Int): Int {
    return a + b
}

inline fun inlineAdd(a: Int, b: Int): Int {
    return a + b
}

// Your code here
// Call both functions and store results

Need a hint?

Use val to create variables normalResult and inlineResult. Call the functions with 10 and 20.

4

Print the results of both function calls

Write two println statements to print the values of normalResult and inlineResult.

Kotlin

fun add(a: Int, b: Int): Int {
    return a + b
}

inline fun inlineAdd(a: Int, b: Int): Int {
    return a + b
}

val normalResult = add(10, 20)
val inlineResult = inlineAdd(10, 20)

// Your code here
// Print the results

Need a hint?

Use println(normalResult) and println(inlineResult) to show the results.