Print Hello World

fun main() {
    println("Hello World")
}

Variable Mutable and Immutable

var mutableVar = "Hello"
mutableVar = "World"
val immutableVar = "Hello World"

Challenge

Strong Typing and Inference

val stringVariable = "Type is inferred as String"
val doubleVariable = 120.3
val explicitTyping: Int
explicitTyping = 202

Challenge

Type Conversion

val one = 1
val oneHundred = "100"
val sum = oneHundred.toInt() + one

String Interpolation

val integerInsideString = "I am Mozzlog. I was born at 2023"

Basic Data Type

val integerValue = 1
val doubleValue = 1.2
val floatValue: Float = 1.23f
val stringValue = "this is string"
val tupleValue = Pair(integerValue, doubleValue)

Collection Basic: Array

val arrayOfString = arrayOf("Hello", "World")
val arrayOfInteger = arrayOf(1, 2)
val arrayOfDouble = arrayOf(10.0, 21.2)
val mixedArray = arrayOf("String", 1, 10.2)

Challenge

Collection Key Value: Dictionary (Map)

val dictWithKeyStringAndValueString = mapOf(
    "Hello" to "World",
    "Good" to "Morning"
)
val dictWithKeyStringAndValueAny = mapOf(
    "Hello" to 1,
    "Good" to "Morning"
)
val dictWithKeyAnyAndValueString = mapOf(
    "Hello" to "World",
    1 to "Morning"
)

Collection Without Duplication: Set

val setOfNames = setOf("Kotlin", "Swift")

Function

fun sayHelloWorld() {
    println("Hello World")
}

Function With Parameter

fun sayMyName(name: String) {
    println("Your name is $name")
}

sayMyName("Heisenberg")

Function With Return Value

fun getReturnValue(value: Int): Int {
    return value
}

val value = getReturnValue(1002)

Function With Return Type Tuple (Pair)

fun createTuple(value: Int): Pair<Int, Int> {
    return Pair(value, value)
}

val (value1, value2) = createTuple(231)

Class

class StandardClass

Class With Member

class StandardClass {
    val member = "default"
    fun printMember() {
        println(member)
    }
}

val obj = StandardClass()
obj.printMember()

Class With Initializer

class StandardClass(val memberInt: Int, var memberDefault: String = "") {
    init {
        memberDefault = "changed"
    }
}

val obj = StandardClass(20)
val obj2 = StandardClass(20, "changed")

Data Class

data class StandardStruct(val memberInt: Int, var memberDefault: String = "")

Challenge

Hint