Kotlin Arrays: A Comprehensive Tutorial with Examples

Introduction to Kotlin Arrays

In Kotlin, arrays are used to store a fixed-size sequential collection of elements of the same type. This tutorial will guide you through the basics of Kotlin arrays, including initialization, accessing elements, modifying arrays, and more.

1. Initializing Arrays

1.1. Declaring Arrays

You can declare an array in Kotlin using the arrayOf() function or the Array constructor.

// Using arrayOf() function
val numbers = arrayOf(1, 2, 3, 4, 5)

// Using Array constructor
val vowels = Array(5) { "" } // Creates an array of size 5 initialized with empty strings

1.2. Primitive Type Arrays

For primitive types like Int, Boolean, etc., Kotlin provides specialized array classes such as IntArray, BooleanArray, etc.

val intArray = IntArray(3) // Creates an IntArray of size 3
val booleanArray = BooleanArray(4) // Creates a BooleanArray of size 4

2. Accessing Elements

You can access elements of an array using the index notation [index].

val fruits = arrayOf("Apple", "Banana", "Orange")
println(fruits[0]) // Output: Apple

3. Modifying Arrays

Arrays in Kotlin are mutable, meaning you can change the elements after the array has been created.

val numbers = arrayOf(1, 2, 3, 4, 5)
numbers[2] = 10
println(numbers.contentToString()) // Output: [1, 2, 10, 4, 5]

4. Array Iteration

You can iterate over the elements of an array using various methods like for loop, forEach function, etc.

val numbers = arrayOf(1, 2, 3, 4, 5)

// Using for loop
for (num in numbers) {
    println(num)
}

// Using forEach function
numbers.forEach { println(it) }

5. Array Functions

Kotlin provides several useful functions for array manipulation like size, contains, indexOf, slice, etc.

val numbers = arrayOf(1, 2, 3, 4, 5)

println(numbers.size) // Output: 5
println(numbers.contains(3)) // Output: true
println(numbers.indexOf(4)) // Output: 3
println(numbers.slice(1..3)) // Output: [2, 3, 4]

Conclusion

This tutorial covered the basics of Kotlin arrays, including initialization, accessing elements, modifying arrays, iteration, and array functions. With this knowledge, you can effectively work with arrays in Kotlin for various applications.