Basics Of Kotlin

https://onecompiler.com/kotlin

Basic Print 

fun main() {
    print("Hello, World!")
    println("Hello, World!")
}

Output:

Hello, World!

Hello, World!

Variables

fun main() {

  val popcorn = 5    // There are 5 boxes of popcorn
  val hotdog = 7     // There are 7 hotdogs
  var customers = 10 // There are 10 customers in the queue
  
  // Some customers leave the queue
  customers = 8
  println(customers)
  // 8  
}

Output:

8

String templates

fun main() {

val customers = 10
println("There are $customers customers ")
// There are 10 customers

println("There are ${customers + 1} customers")
// There are 11 customers
}

Output:

There are 10 customers 
There are 11 customers

Data Types:

String,Double,Boolean

fun main() {
    var name: String = "AEC"
    var year: Int = 2025
    var dv: Double = 2025.25
    var bc: Boolean = true


    println("name ${name}")
    println("year ${year}")
    println("dv ${dv}")
    println("bc ${bc}")
            
}
Output:

name AEC
year 2025
dv 2025.25
bc true

If Statement :

Syntax:

if(condition){

do this

}else{do this}

fun main() {
    var password: String = "1234"
    var givenpassword: String = "1234"
    
    if(givenpassword.equals(password)){
      
      print("Password is Correct")
    }
    else{
      print("Password incorrect")
    }

}

Output:

Password is Correct



fun main() {
    var age:Int=19
    
    if(age>18){
      
      print("Voter id Generated")
    }
    else{
      print("Wait")
    }

}
Output:

Voter id Generated

When Statement same like (C switch)

Syntax:

when(variable){

variableval1->{do this}

variableval2->{do this}

variableval3->{do this}

variableval4->{do this}

variableval5->{do this}

}else{do this}

fun main() {
    val day = 3
    when (day) {
        1 -> {print("Monday") }
        2 -> {print("Tuesday")}
        3 -> {print("Wednesday")}
        else -> {print("Invalid day")}
    }

}

Output:

Wednesday

fun main() {
    val day = 3
    val dayName = when (day) {
        1 -> "Monday"
        2 -> "Tuesday"
        3 -> "Wednesday"
        else -> "Invalid day"
    }
    println(dayName)
}
Output:

Wednesday

in Key Word

fun main() {
    val marks:Int = 60
    when (marks) {
        in 70..100->{print("First Class")}
        in 50..69->{print("Second Class")}        
        else -> {print("Fail")}
    }

}
Output:

Second Class

Loops 

fun main() {
    var i: Int = 1
    while (i <= 5) {
        println("Android Tech")
        i = i + 1
    }
}
Output:

Android Tech
Android Tech
Android Tech
Android Tech
Android Tech

For Loop

fun main() {

  for(item in 1..10){
    println("Loop ${item} $item")
  }
  
}

Output:

Loop 1 1
Loop 2 2
Loop 3 3
Loop 4 4
Loop 5 5
Loop 6 6
Loop 7 7
Loop 8 8
Loop 9 9
Loop 10 10

Break

fun main() {

  for(item in 1..10){
    println("Loop ${item} $item")
    if(item==5){
      break
    }
    
  }
  
}
Output:

Loop 1 1
Loop 2 2
Loop 3 3
Loop 4 4
Loop 5 5

Continue Stmt

fun main() {

  for(item in 1..10){
    
    if(item == 5){
      continue
    }
    println("Loop ${item} $item")
    
  }
  
}
Output:

Loop 1 1
Loop 2 2
Loop 3 3
Loop 4 4
Loop 6 6
Loop 7 7
Loop 8 8
Loop 9 9
Loop 10 10

arrayOf

fun main() {
    val fruits = arrayOf("Apple", "Banana", "Cherry", "Mango")
    //val fruits = arrayOf<String>("Apple", "Banana", "Cherry", "Mango")
    for (fruit in fruits) {
        println(fruit)
    }
}

Output:

Apple
Banana
Cherry
Mango

Array 

fun main() {
    val names = arrayListOf<String>("A", "B", "C", "D")
    println(names.get(2))
    names.add("E")

    for (name in names) {
        println(name)
    }
    //names.remove(element:"C")
    names.remove("C")
    for (name in names) {
        println(name)
    }
  names.removeAll(names)
  println(names)
  
}


Output:

C
A
B
C
D
E
A
B
D
E
[]

Functions Calls

fun main() {
    sample()
    
}

fun sample(){
  println("Hi Hello")
}

Output:
Hi Hello

& 
fun main() {
    sample()
    addition(num1=10,num2=20)
}

fun sample(){
  println("Hi Hello")
}

fun addition(num1:Int,num2:Int){
  println(num1+num2)
  
}
Output:

Hi Hello
30

Ex02

fun main() {
    sample()
    addition(num1=10,num2=20)
    multiplicationTable(number=3)
  
}

fun sample(){
  println("Hi Hello")
}

fun addition(num1:Int,num2:Int){
  println(num1+num2)
  
}
fun multiplicationTable(number:Int){
  var ouput:String?=""
  
  
  for(i in 1..12){
    print("$number X $i = "+(number*i))
    print("\n")
    
  }
  
}

Output:

Hi Hello
30
3 X 1 = 3
3 X 2 = 6
3 X 3 = 9
3 X 4 = 12
3 X 5 = 15
3 X 6 = 18
3 X 7 = 21
3 X 8 = 24
3 X 9 = 27
3 X 10 = 30
3 X 11 = 33
3 X 12 = 36