🚀 Let's start

Prerequisites

Basic knowledge of kotlin development (nullability,inline & lambda functions mainly). For more information, please refer to the Worldline kotlin trainingopen in new window
Fleet IDEopen in new window is the dedicated IDE to consider for KMP developpement with exclusive features such as better preview management
A good connectivity

Advanced installation

For more information about your DEV environment and installs please have a look to jetbrain related docsopen in new window

Consider also installing Jetbrain ToolBoxopen in new window for managing multiple versions ( Beta , Alpha , stable) of Android Studio or Fleet

What is Functional Programming?

Definition:

FP uses an approach to software development that uses pure functions to create maintainable software
It uses immutable functions and avoids shared states.
It is in contrast to object-oriented programming languages which uses mutable states
It focuses on results and not process, while the iterations like for loops are not allowed

Advantages: Problems are easy Keeps concurrency safe

let numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

// Step 1: Filter out even numbers
let oddNumbers = numbers. filter { $0 % 2 != 0 }

// Step 2: Square each of the remaining numbers
let squaredNumbers = oddNumbers.map { $0 * $0 }

// Step 3: Sum up all the squared numbers
let sumOfSquares =squaredNumbers.reduce(0, +)

print("The sum of squares of odd numbers is \(sumOfSquares)")
//output: The sum of squares of odd numbers is 165

Filter: filters array to include only odd numbers Map: squares the numbers Reduce: sums up the squared numbers

This example demonstrates the core principles of functional programming: using functions as first-class citizens to transform and compose data in a clear and concise way.

Apps using KMP

capture

KMP roadmap

See the roadmap 2024 on official Jetbrain blogopen in new window

Hands-on Lab objectives

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Functionnally

We will create a simple quiz application that provides :

a Startup screen explaining rules of the game
a Quiz screen looping on single choices questions
a final scoring screen.

Technically

The app can be deployed on Android , iOS and jvm Desktop.
We will use not only a common library but composable views shared for all platforms

Design screens

Here are expected screens at the end of this Hands-on Lab.

screens

Generate composables based on designs

You can generate composables based on designs on Figma thanks to the plugin Google Relayopen in new window. A dedicated section on android developer documentation describe all the steps hereopen in new window

# 🚀 Let's start

# Prerequisites

# What is Functional Programming?

# Apps using KMP

# KMP roadmap

# Hands-on Lab objectives

# Functionnally

# Technically

# Design screens

# See also