Introduction

This tutorial aims to get you started with Kotlin for Android development. Kotlin is a modern, statically-typed programming language that boosts productivity and increases developer happiness. It's officially supported by Google for Android development and is widely admired for its conciseness, safety features, and interoperability with Java.

By the end of this tutorial, you'll be able to:

• Set up Kotlin in Android Studio
• Understand basic Kotlin syntax and concepts
• Write your first Android app in Kotlin

Prerequisites:
Basic knowledge of programming concepts (like variables, functions, and classes) is helpful. Familiarity with Java and Android development would be a bonus but is not necessary.

Step-by-Step Guide

1. Setting up Kotlin in Android Studio

To start with Kotlin for Android, you need to have Android Studio installed. You can download the latest version from the official website. Android Studio has built-in support for Kotlin. When you create a new Project, just select 'Kotlin' as your language.

2. Understanding Kotlin Syntax

Kotlin syntax is clean and intuitive. Here's how you can define variables:

var mutableVariable: Int = 10  // Mutable variable
val immutableVariable: Int = 5 // Immutable variable (similar to final in Java)

Functions are defined using the 'fun' keyword:

fun greet(): String {
    return "Hello, Kotlin!"
}

3. Writing Your First Android App in Kotlin

To write an Android app in Kotlin, go to 'File -> New -> New Project'. Select 'Empty Activity', and then select 'Kotlin' as the language.

Code Examples

Let's understand more Kotlin concepts with examples:

1. Null Safety

Kotlin provides built-in null safety. Let's see it in action:

var nonNullableVar: String = "Hello"  
nonNullableVar = null // Compilation error

var nullableVar: String? = "Hello"  
nullableVar = null // OK

2. Functions

// Function without parameters and return type
fun printHello() {
    println("Hello, Kotlin!")
}

// Function with parameters and return type
fun addNumbers(a: Int, b: Int): Int {
    return a + b
}

Summary

In this tutorial, we've covered how to set up Kotlin in Android Studio, basic Kotlin syntax, and writing your first Android app in Kotlin. As next steps, you can explore more features of Kotlin like its Object-Oriented Programming (OOP) support, exception handling, and collection framework.

Practice Exercises

1. Write a function in Kotlin that takes two integers as input and returns their product.
2. Write a Kotlin program that checks if a number is even or odd.
3. Create a simple Android app to display a "Hello, Kotlin!" message on the screen.

Solutions

1. Function to multiply two numbers:

fun multiply(a: Int, b: Int): Int {
    return a * b
}

1. Program to check if a number is even or odd:

fun checkNumber(n: Int) {
    if (n % 2 == 0) {
        println("The number is even.")
    } else {
        println("The number is odd.")
    }
}

1. Android app to display a message:

import android.widget.TextView
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val textView = findViewById<TextView>(R.id.text_view)
        textView.text = "Hello, Kotlin!"
    }
}

In the XML file, you should have a TextView with id 'text_view'.

Continue to practice, and happy Kotlin coding!