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Articles by Soumak De
Page 2 of 7
How to check generic type in Kotlin?
In this article, we will see how we can get the type of a class that is used in Kotlin. There are no direct ways to do this in Kotlin. In order to check the generic type, we need to create an instance of the generic class and then we can compare the same with our class.ExampleFor this example, we will create a generic class of type and we will pass our variable inside this class in order to check its type.class MyGenericClass(val myclass: Class) { companion object { inline operator fun invoke() = MyGenericClass(T::class.java) ...
Read MoreKotlin equivalent of Java's equalsIgnoreCase
Java provides a String method called equalsIgnoreCase() which helps developers to compare two strings on the basis of their content. This comparison is case-insensitive, that is, it ignores whether the strings are in uppercase or lowercase and just compares the string values. In this article, we will see how we can implement the same functionality in Kotlin.Example – equalsIgnoreCase in JavaThe following example demonstrates how equalsIgnoreCase() works in Java.public class MyClass { public static void main(String args[]){ String s1="TutorialsPoint"; String s2="tutorialspoint"; System.out.println("String 1: " ...
Read MoreHow to implement switch-case statement in Kotlin?
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 ...
Read MoreHow to correctly concatenate strings in Kotlin?
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 ...
Read MoreCreating POJO Class for Kotlin
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 ...
Read MoreGetters and Setters in Kotlin
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 ...
Read MoreDifference between isNullOrEmpty and isNullOrBlank in Kotlin
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 ...
Read MoreIntArray vs. Array in 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 MoreWhat does the "===" operator do in Kotlin?
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 MoreHow to print all the elements of a String array in Kotlin in a single line?
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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