Single-expression functions in Kotlin - Mini Project: Build & Apply

Single-expression functions

📖 Scenario: You are building a simple calculator app that needs to perform basic math operations quickly and clearly.

🎯 Goal: Create single-expression functions in Kotlin to perform addition, subtraction, multiplication, and division.

📋 What You'll Learn

Create single-expression functions for addition, subtraction, multiplication, and division

Use concise syntax without curly braces or return statements

Call each function with example inputs

Print the results of each function call

💡 Why This Matters

🌍 Real World

Single-expression functions help write clean and simple code for small tasks like calculations in apps.

💼 Career

Understanding concise function syntax is useful for Kotlin developers to write readable and maintainable code efficiently.

1

Create addition function

Create a single-expression function called add that takes two Int parameters named a and b and returns their sum.

Kotlin

# Create a single-expression function called add(a: Int, b: Int) that returns a + b
// Your code here

Need a hint?

Use the equals sign = to define a single-expression function without curly braces.

2

Create subtraction function

Create a single-expression function called subtract that takes two Int parameters named a and b and returns the result of a - b.

Kotlin

fun add(a: Int, b: Int) = a + b
# Create a single-expression function called subtract(a: Int, b: Int) that returns a - b
// Your code here

Need a hint?

Follow the same pattern as the add function but use subtraction.

3

Create multiplication and division functions

Create two single-expression functions: multiply and divide. Both take two Int parameters named a and b. multiply returns a * b. divide returns a / b.

Kotlin

fun add(a: Int, b: Int) = a + b
fun subtract(a: Int, b: Int) = a - b
# Create single-expression functions multiply(a: Int, b: Int) and divide(a: Int, b: Int)
// Your code here

Need a hint?

Use the same single-expression function style for multiplication and division.

4

Print results of function calls

Call each function with the arguments 10 and 5. Print the results using println with messages: "10 + 5 = result", "10 - 5 = result", "10 * 5 = result", and "10 / 5 = result".

Kotlin

fun add(a: Int, b: Int) = a + b
fun subtract(a: Int, b: Int) = a - b
fun multiply(a: Int, b: Int) = a * b
fun divide(a: Int, b: Int) = a / b
# Call each function with 10 and 5 and print the results
// Your code here

Need a hint?

Use string templates with ${} inside println to show results.