FUNCTION KOTLIN PROGRAMS

1.//Standard Library Function 

fun main(args: Array<String>) 
{
   // arrayOf()-- to create an array by passing the values of the elements to the function.
	var sum = arrayOf(1,2,3,4,5,6,7,8,9,10).sum()

	println("The sum of all the elements of an array is: $sum")
}

Output:

The sum of all the elements of an array is: 55


2.//  Kotlin user-defined function student() having different types of parameters-
fun student(name: String , roll_no: Int , grade: Char) 
{
	println("Name of the student is : $name")
	println("Roll no of the student is: $roll_no")
	println("Grade of the student is: $grade")
    
}

fun main(args: Array<String>) {
    var result = student("CSE-B",66,'A')
    println("Details of Student: $result")
}
Output:
Name of the student is : CSE-B
Roll no of the student is: 66
Grade of the student is: A 

[OR]


//  Kotlin user-defined function student() having different types of parameters-
fun student(name: String , roll_no: Int , grade: Char) {
	println("Name of the student is : $name")
	println("Roll no of the student is: $roll_no")
	println("Grade of the student is: $grade")
    
}

fun main(args: Array<String>) {
    student("CSE-B",66,'A')
    
}

Output:
Name of the student is : CSE-B
Roll no of the student is: 66
Grade of the student is: A




3. //  function with parameter & with return type               
fun CSE_B(x: Int): Int 
{
  return (x + 5)
}

fun main() 
{
  var result = CSE_B(3)
  println(result)
}

Output:

8



4.//  function WITHOUT PARAMETERS & WITHOUT RETURN TYPE              
fun  CSE_B()
{
  println("WELCOME TO MAD LAB")
}

fun main() 
{
  CSE_B()
 
}

Output:

WELCOME TO MAD LAB




5.//  demonstrate how to pass a variable number of arguments to a function  Using vararg              
fun main (args: Array<String>)
{
   CSE_B ( "abc", "def", "ghi", "123", "sun")
}

fun CSE_B (vararg a: String) 
{
    for (a_ in a) 
    {
	    println(a_)
    }
}

Output:

abc
def
ghi
123
sun


6.//  lambda function              
fun main(args: Array<String>){  
   val myLambda: (Int) -> Unit= {s: Int -> println(s) } //lambdafunction  
    addNumber(5,10,myLambda)  
}  
//The variable mylambda in function definition is actually a lambdafunction.
fun addNumber(a: Int, b: Int, mylambda: (Int) -> Unit ){   
    //high level function lambda as parameter  
    val add = a + b  
    mylambda(add) // println(add)  
}

Output:
15 


7.//  lambda function              
// with type annotation in lambda expression
val sum1 = { a: Int, b: Int -> a + b }
// Kotlin program of using lambda expression-
//  without type annotation in lambda expression
val sum2:(Int,Int)-> Int = { a , b -> a + b}
fun main(args: Array<String>) 
{
	val result1 = sum1(2,3)
	val result2 = sum2(3,4)
	println("The sum of two numbers is: $result1")
	println("The sum of two numbers is: $result2")
	// directly print the return value of lambda
	// without storing in a variable.
	println(sum1(5,7))     
}

Output:

The sum of two numbers is: 5
The sum of two numbers is: 7
12


8.// anonymous function 

// anonymous function  with body as an expression
val anonymous1 = fun(x: Int, y: Int): Int = x + y
// anonymous function with body as a block
val anonymous2 = fun(a: Int, b: Int): Int 
{
			val mul = a * b
			return mul
}
fun main(args: Array<String>) 
{
	//invoking functions
	val sum = anonymous1(3,5)
	val mul = anonymous2(3,5)
	println("The sum of two numbers is: $sum")
	println("The multiply of two numbers is: $mul")
}

Output:
The sum of two numbers is: 8
The multiply of two numbers is: 15



9.//Kotlin program of lambda expression which returns Unit-	
var lambda = {println("WELCOME TO CSE-B MAD LAB")}  
   // lambda expression
	// higher-order function
fun higherfunc( lmbd: () -> Unit )
{	 // accepting lambda as parameter
	lmbd()		//invokes lambda expression
}
fun main(args: Array<String>) 
{
	//invoke higher-order function
	higherfunc(lambda)   // passing lambda as parameter
}


Output:

WELCOME TO CSE-B MAD LAB



10. //Kotlin program of lambda expression which returns Integer value –  	
var lambda = {a: Int , b: Int -> a + b }         // lambda expression
	// higher order function
fun higherfunc( lmbd: (Int, Int) -> Int) 
{	 
    // accepting lambda as parameter	
	var result = lmbd(2,4)               // invokes the lambda expression by passing parameters				
	println("The sum of two numbers is: $result")
}
fun main(args: Array<String>) 
{
	higherfunc(lambda)  //passing lambda as parameter
}

Output:

The sum of two numbers is: 6




11. //Take input from user using readline() method 
fun main(args : Array<String>) {
	println("Enter text: ")
	var input = readLine()
	print("You entered: $input")
}

Output:
Enter text:  CSE-B
You entered: CSE-B