Arrays and Lists

Arrays and lists are collection types in Kotlin that allow you to store multiple values in a single variable. While arrays are fixed in size, lists can dynamically grow or shrink. This section will guide you through the basics of arrays and lists in Kotlin.

Arrays

Syntax

The basic syntax for defining an array in Kotlin is as follows:

val arrayName = arrayOf(element1, element2, ...)

Example

Here's a simple array that stores integers.

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

Accessing Elements

You can access elements of an array using their index.

val firstNumber = numbers[0]  // Result: 1

Modifying Elements

Arrays are mutable, meaning you can change their elements.

numbers[0] = 10  // Changes the first element to 10

Lists

Syntax

The basic syntax for defining a list in Kotlin is as follows:

val listName = listOf(element1, element2, ...)

Example

Here's a simple list that stores strings.

val names = listOf("Alice", "Bob", "Charlie")

Accessing Elements

You can access elements of a list using their index.

val firstName = names[0]  // Result: "Alice"

Mutable Lists

Kotlin also provides mutable lists that allow you to add or remove elements.

Syntax

val mutableList = mutableListOf(element1, element2, ...)

Example

val mutableNames = mutableListOf("Alice", "Bob")
mutableNames.add("Charlie")  // Adds "Charlie" to the list

Summary and Best Practices

• Use arrays when the size is fixed and you need fast access to elements.
• Use lists for collections that need to grow or shrink dynamically.
• Prefer using listOf for read-only lists and mutableListOf for lists that will be modified.
• Always specify the type of elements explicitly for better readability.

Arrays and lists are essential for storing collections of data in Kotlin. Whether you're working on data manipulation tasks or building complex Android Native applications, understanding these collection types will help you manage data more effectively.