Found 417 Articles for Kotlin

In this article, we will take an example to show the difference between IntArray and Arrayin Kotlin.IntArray in KotlinIntArray is a class in Kotlin representing the array of elements. Each instance of this class is represented as an integer array. To the constructor of this class you need to pass the number of elements you need in the array (size).You can instantiate this class as shown below −val myArray = IntArray(8)By default, all the elements of the created array will be initialized to "0".ExampleThe following program creates an array of integers by instantiating the IntArray class −fun main(args: Array) { ... Read More

In Kotlin, the "===" operator checks the referential equality of two objects. Any expression "a===b" will evaluate to True if and only if both "a" and "b" point to the same object. That is, both "a" and "b" share the same address.In contrast, we can use the "==" operator to check structural equality which implies that two objects have equivalent content. Basically, "==" is a check for equals().Example: "===" Operator in Kotlinfun main(args: Array) {    var str1 : String = "That's it"    var str2 : String = "It's OK"    var str3 : String = str1   ... Read More

In Java, once a method is declared as "static", it can be used in different classes without creating an object. With static methods, we don't have to create the same boilerplate code for each and every class. Here we will take an example to demonstrate how Kotlin implements static methods.Example – Static Method in Kotlin using Companion ObjectIn order to implement a static method in Kotlin, we will take the help of "companion objects".Companion objects are the singleton objects whose properties and functions are tied to a class but not to the instance of that class. Hence, we can access ... Read More

A List is a collection where you can store same type of data in one place. There are two types of lists in Kotlin −An Immutable list is something that cannot be modified. It is read-only in nature.The other type of list is mutable which can be modified.In this article, we will see how to create a mutable list and how to add an item to the existing list.Example – Adding an Item to a Mutable ListIn order to add an item to a list, we will be using add() that is provided by the Kotlin library class.fun main(args: Array) ... Read More

Kotlin is a statistically typed language and it is based on Java, hence all the Java codes can easily be compiled within Kotlin. In this article, we will see how we can generate the current local date and time in Kotlin.As Kotlin is interoperable with Java, we will be using the Java utility class and Simple Date Format class in order to get the current local date and time.Example – Current Date and time using SimpleDateFormatimport java.text.SimpleDateFormat import java.util.* fun main(args: Array) {    val simpleDate = SimpleDateFormat("dd/M/yyyy hh:mm:ss")    val currentDate = simpleDate.format(Date())    println(" Current Date is: ... Read More

Kotlin is statistically typed language and it is built on JVM. Kotlin is cent percent comparable with Java. Hence, some of the Java functions can be used in Kotlin as well.In this article, we will take an example to demonstrate how we can use a Java class function convert an Int in Kotlin to its correponding Hex String.Example – Converting Int to Hex String in KotlinIn this example, we will use the Java class function toHexString().import java.lang.* fun main(args: Array) {    val hexString = java.lang.Integer.toHexString(-66)    println("Hex String for negative Number: " +hexString)    val positiveNumber ... Read More

In this article, we will take a couple of examples to demonstrate how we can split a given String in Kotlin using some given delimiters.Example – Split a String using given delimitersIn this example, we will create a String and we will store some value in it and we will try to split the same using some delimiters.fun main(args: Array) {    var str = "Tut@or@ia@lsPo@int.@com"    var delimiter = "@"    // It will split the given String using '@'    val parts = str.split(delimiter)    print(parts) }OutputIt will generate the following output −[Tut, or, ... Read More

Switch-case statement in any programming language allows the programmers to testify it against different values. It also provides an option to do something whenever the value of the variable does not match with a given value. In this article, we will take a simple example and demonstrate how we can implement the switch-case statement in Kotlin.Kotlin does not provide any option to write a switch-case statement. However, Kotlin provides an option to implement when() which works exactly the same way switch works in other programming languages.Example – Implementing switch-case in JavaIn this example, we will implement switch-case in Java.public class ... Read More

In this article, we will see three different ways to check whether a String is empty in Kotlin.Example – isEmpty()Kotlin library function isEmpty() can be used in order to check whether a String is empty. Note that it counts spaces too.fun main(args: Array) {    // No space between the quotes    val myString = ""    // Space between the quotes    val anotherString = " "    println(myString.isEmpty())    // this will return false as we have a space    println(anotherString.isEmpty()) }OutputOn execution, it will produce the following output −true falseObserve that the second ... Read More

Kotlin provides four types of constructors to define and manipulate a HashMap. In this article, we will see how we can reverse a map using Kotlin library function.A Map is a collection where data is stored as a key-value pair and the corresponding key has to be unique.A HashMap is a collection class based on MutableMap interface and it does that by implementing the MutableMap interface of HashTable.Example − Reverse using Iterable associate()In this example, we will create a HashMmap and we will reverse the same using associate(). In this method, we will be creating a new map and we ... Read More