Answers for "kotlin fun"

function in kotlin

- function syntax
        - first fun keywords
        - second function name and arguments
        - : return type otherwise nothing

    "simple funtion"
        # fun myFunction(){
        #     println("Printing from inside the function")
        # }

    "function with arguments"
        - argument cann't be changed 
        - it can be changed only when anyother variable inside the function holds its value
            # fun sum(num1:Int , num2:Int){
            #     println("Sum of $num1 and $num2 = ${num1+num2}")
            # }

    "return value form function"
        - if function don't return anything than it return "Unit" 
        - "unit" is equal to "Void"
        - unit is not meaningful thing
            # fun sum(num1:Int , num2:Int): Int {
            #     var result = num1+num2
            #     return result
            # }

            # fun sum(num1:Int , num2:Double): Double {
            #     return num1+num2
            # }

            # fun sum(num1:Int , num2:Double): Double { return if (num1<0) num1+num2 else num1-num2 }

    "return Nothing from function and terminating the function"
        # fun myFunction():Nothing{
        #     println("Printing from inside the function")
        #     throw Exception("my expection")
        # }

    "default value function"
        - default parameter must be last one other wise error will come
        - you can use named parameters
            # fun showName (name:String , numOfStart:Int = 5){
            #
            #     for (i in 0..numOfStart) print("*")
            # 
            #     println()
            #     println(name)
            # 
            #     for (i in 0..numOfStart) print("*")
            # }

    "named parameters"
        - named parameter are default parameter but at starting 
        - when function is called than parameter must be given to it
            # fun multiplyValues(num1:Int=5 , num2:Int){
            #     println("$num1 times $num2 is ${num1*num2}")
            # }
            # multiplyValues(num2 = 5)

    "single expression functions"
        - when function only return only expression
            # fun sum(num1:Int, num2: Double): Double = num1+num2
            # fun sum(num1:Int, num2: Double): Any = if (num1<10) -1 else num1+num2

    "vargs functions"
        - when we want to pass large number of parameters
        - it may be last one other wise we have to use named parameters
            # fun product(num1:Int,num2:Int,vararg num3:Int): Int {
            #     var result = 1
            #     for (i in num3){
            #         result *= i
            #     }
            #     return num1*num2*result
            # }
            # val result = product(10,10,10,10,10,10,10,10,2,3,5,8,9)
        
        - to pass array in vargs we have to you "*" before array name in invoking function
            # fun product(num1:Int,num2:Int,vararg num3:Int): Int {
            #     var result = 1
            #     for (i in num3){
            #         result *= i
            #     }
            #     return num1*num2*result
            # }
            # val intArray = intArrayOf(1,2,3,4,5,6,7,89,1)
            # val result = product(10,10,*intArray)

kotlin function

fun sum(a: Int, b: Int): Int {
 return a + b
}

make function kotlin

fun main() {
	println("This is a function")
}

function in kotlin

kotlin function