Kotlin Functions

FAQ

Q. What is Unit return type?
A. Unit return type is used when we have nothing to return from a function.

Q. Is it possible to return multiple values from a function?
A. Yes, it can be done using Pair or Triple, Pair returns two values and Triple returns three values.

Q. What to do if we need multiple parameters in a funtion but are not sure of the exact number?
A. In such a case, we can use varargs that allows us to pass any number of parameters.

Q. What type of function is this fun add(num1: Int, num2: Int) : Int = num1 + num2?
A. This is called single line function, it does not have a complete body and it return the values written after the equals sign.

MCQ

Q. Which is a correct function declaration?
a) fun add(num1 :Int, num2 :Int) : Int = num1 + num2
b) fun subtract(num1: Int = 1, num2: Int = 1) = num1 - num2
c) val mult = {num1 : Int, num2 : Int -> num1 * num2}
d) All of these
e) None of these

A. d) All of these

Q. Which of the following code will work correctly?
 1. fun main() {
      println("5 + 7 = ${add(5, 7)}")
      fun add(num1 :Int, num2 :Int) : Int = num1 + num2
    }
    
 2. fun main() {
      fun add(num1 :Int, num2 :Int) : Int = num1 + num2
      println("5 + 7 = ${add(5, 7)}")
    }
    
 3. fun main() {
      println("5 + 7 = ${add(5, 7)}")
    }
    fun add(num1 :Int, num2 :Int) : Int = num1 + num2
    
a) 1 and 2
b) 2 and 3
c) 3 and 1
d) None of these

A. b) 2 and 3

Q. Which is the correct syntax for using variable arguments in a function?
a) vararg nums: Int
b) Vararg nums: Int
c) nums : varargs
d) None of these

A. a) vararg nums: Int

Q. What will be the output?
    fun main() {
        print(myFun())
    }
    fun myFun() : Int {
        print("Hello")
        return 5
    }
a) 5Hello
b) Hello5

A. b) Hello5