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How to implement switch-case statement in Kotlin?

Soumak De
Soumak De
Updated on 16-Mar-2022 9K+ Views

Switch case statement in any programming language is a type of selection control mechanism that allows the developers to test the value of a variable or expression and change the control flow of a program based on the outcome of the comparison. It also provides an option to do something whenever the value of the variable does not match a given value.Kotlin does not provide an option to write a switch-case statement; however we can implement the switch-case functionality in Kotlin using the when() function which works exactly the same way switch works in other programming languages.In this article, we ...

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How to correctly concatenate strings in Kotlin?

Soumak De
Soumak De
Updated on 16-Mar-2022 9K+ Views

There are different ways to concatenate strings in Kotlin. For example, we can use the $ operator or we can use the append() function or we can simply use the "+" operator to join two strings.Example – Concatenate Using "$"Kotlin provides an operator to reference a variable or expression. In this example, we will see how to concatenate two strings using the "$" operator.fun main(args: Array) {    val a = "Tutorialspoint"    val b = ".com"    println("String 1: " + a)    println("String 2: " + b)    println("Concatenated String: " + "$a$b") }OutputIt will produce the following ...

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Creating POJO Class for Kotlin

Soumak De
Soumak De
Updated on 16-Mar-2022 3K+ Views

Kotlin has been developed over JVM and hence it is fully compatible with JVM. Java POJO class stands for Plain Old Java Object (POJO) which is used to hold the data.In Java, along with defining the variables, we need to create different supporting methods in order to access those private members of the class.But Kotlin provides a unique way to declare a POJO class by introducing the "data" keyword. It can be applied along with class.Once a class is defined as data class, the Kotlin compiler itself will be creating all the supporting getter() and setter() methods for this class.Example ...

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Getters and Setters in Kotlin

Soumak De
Soumak De
Updated on 16-Mar-2022 736 Views

Properties in Kotlin can be declared either as mutable using the "var" keyword or as read-only using the "val" keyword. Both these types of variables can be referred by their respective names after the method declaration.In Kotlin, getter() and setter() methods need not be created explicitly. The Kotlin library provides both of them by default.ExampleIn this example, we will see how to use the getter() and setter() methods in Kotlin.fun main(args: Array) {    // getter()    println("Name is -> " + Address().name)    println("City is -> " + Address().city)    println("State is -> " + Address().state) } class Address ...

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Difference between isNullOrEmpty and isNullOrBlank in Kotlin

Soumak De
Soumak De
Updated on 16-Mar-2022 2K+ Views

Both these functions, isNullOrEmpty and isNullOrBlank, are used in Kotlin whenever it is required to check if a String value is empty or not. Let's check how these two functions are different from each other.isNullOrBlank – It takes whitespaces into account, which means " " is different from "". This function will return True only when the String is declared with no characters in it. It will check whether the value of the String is NULL and it will also check whether the String is blank.isNullOrEmpty() – This function checks whether the string is declared as NULL or whether it ...

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IntArray vs. Array in Kotlin

Soumak De
Soumak De
Updated on 16-Mar-2022 8K+ Views

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) { ...

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What does the "===" operator do in Kotlin?

Soumak De
Soumak De
Updated on 16-Mar-2022 532 Views

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   ...

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How to print all the elements of a String array in Kotlin in a single line?

Soumak De
Soumak De
Updated on 01-Mar-2022 747 Views

In this article, we will take an example and show how to print all the elements of a String array in a single line using a Kotlin library class. In order to do that, we will use a String function called joinToString(), provided by the Kotlin library.As per the Kotlin documentation, the function definition looks like this −fun Array.joinToString(    // the String will be separated by this    separator: CharSequence = ", ",    // This will be added as prefix to the String    prefix: CharSequence = "",    // This will be added as postfix ...

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How to add an item to a list in Kotlin?

Soumak De
Soumak De
Updated on 01-Mar-2022 946 Views

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) ...

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How to get the current local date and time in Kotlin?

Soumak De
Soumak De
Updated on 01-Mar-2022 4K+ Views

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: ...

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