Found 1879 Articles for Mobile Development

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

Soumak De
Updated on 01-Mar-2022 12:07:10
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

How to convert Int to Hex String in Kotlin?

Soumak De
Updated on 01-Mar-2022 12:03:40
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

How to split a String into an array in Kotlin?

Soumak De
Updated on 01-Mar-2022 12:00:07
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

Kotlin 'when' statement vs Java 'switch'

Soumak De
Updated on 01-Mar-2022 11:56:33
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

How to check if a string is empty in Kotlin?

Soumak De
Updated on 01-Mar-2022 11:45:39
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

How to reverse a Map in Kotlin?

Soumak De
Updated on 01-Mar-2022 11:41:15
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

How to convert TimeStamp to DateTime in Kotlin?

Soumak De
Updated on 01-Mar-2022 11:37:27
Kotlin is a statistically typed language and it is based on Java, hence all the Java code can easily be compiled within Kotlin code. 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 Java utility class and Simple Date Format class in order to convert TimeStamp into DateTime.Example – Converting DateTime using Java util classAs Kotlin is comparable with the JVM, we can use the Java util class in order to convert the TimeStamp into DateTime.import java.text.SimpleDateFormat import java.util.* fun main(args: ... Read More

Print 0001 to 1000 in Kotlin with padding

Soumak De
Updated on 01-Mar-2022 11:33:48
In this example, we will see how to print 0001 to 1000 in Kotlin with padding. For this purpose, we will use a Kotlin library function called padStart().padStart is a function which returns a charSequence. Its function definition looks like this −fun CharSequence.padStart( length: Int, padChar: Char = ' ' ): CharSequenceExample – Print 0001 to 1000 with paddingThe following code prints 1 to 1000 with padding.fun main(args: Array) {    (1..1000).forEach{println("$it".padStart(4, '0'))} }OutputOn execution, it will print a sequence of 4-digit numbers starting from 0001 to 1000.0001 0002 0003 0004 ... ... ... 0996 0997 0998 0999 1000

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

Soumak De
Updated on 01-Mar-2022 13:28:41
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 ... Read More

Equality checks in Kotlin (Difference between "==" and "===" Operators)

Soumak De
Updated on 01-Mar-2022 11:16:42
Kotlin is statistically typed language and it is hundred percent comparable with Java, as it was developed based on JVM. In Kotlin, there are two types of equality checks −One is denoted by "==" andThe other one is denoted by "===".As per the official documentation, "==" is used for structural equality, whereas "===" is used for referential equality.For any expression, a==b will evaluate to True only when the value of both "a" and "b" are equal.a===b will evaluate to True only when both "a" and "b" are pointing to the same object.Example – Equality in KotlinIn this example, we will ... Read More
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