Kotlin Quiz - Find the Output

What is the output of the following code?

fun square(num: Int): Int { return num * num }

fun main() { val result = square(5) println("The square of 5 is: $result") }

• The square of 5 is: 10

• 25

• The square of 5 is: 25

• square(5)

Answer explanation

The function 'square' calculates the square of the input number. When 'square(5)' is called, it returns 25. The output statement then prints 'The square of 5 is: 25', making the correct choice 'The square of 5 is: 25'.

What is the output of the following code? fun factorial(n: Int): Int { return if (n == 0) 1 else n * factorial(n - 1) } fun main() { val num = 5 val result = factorial(num) println("Factorial of $num is $result") }

• 120

• 25

• Factorial of 5 is 120

• 5

Answer explanation

The code calculates the factorial of 5 using recursion. The factorial of 5 is 5 * 4 * 3 * 2 * 1 = 120. The output statement prints 'Factorial of 5 is 120', making the correct choice 'Factorial of 5 is 120'.

What is the output of the following code? fun add(a: Int, b: Int): Int = a + b fun calculate(x: Int, y: Int, operation: (Int, Int) -> Int): Int { return operation(x, y) } fun main() { val result = calculate(10, 5, ::add) println("Result: $result") }

• 10

• 15

• Result: 15

• Error

Answer explanation

The function 'add' takes two integers and returns their sum. In 'calculate', 'operation' is passed as '::add'. Thus, 'calculate(10, 5, ::add)' computes 10 + 5, resulting in 15. The output is 'Result: 15'.

What is the output of the following code? fun main() { val square = { x: Int -> x * x } val result = square(6) println("Square is: $result") }

• 36

• 6

• Square is: 36

• Error

Answer explanation

The code defines a lambda function 'square' that calculates the square of an integer. When called with 6, it returns 36. The result is printed as 'Square is: 36', making this the correct output.

What is the output of the following code? inline fun greet(block: () -> Unit) { println("Before greeting") block() println("After greeting") } fun main() { greet { println("Hello, Nisha!") } }

• Before greeting Hello, Nisha! After greeting

• Hello, Nisha! After greeting

• Only Before greeting

• Compilation Error

Answer explanation

The code defines a function 'greet' that prints a message before and after executing a block of code. When 'greet' is called in 'main', it prints 'Before greeting', executes the block (printing 'Hello, Nisha!'), and then prints 'After greeting'. Thus, the output is 'Before greeting Hello, Nisha! After greeting'.

What is the output of the following code? val age = 18 if (age < 13) { println("Child") } else if (age in 13..17) { println("Teenager") } else { println("Adult") }

• Teenager

• Adult

• Child

• Error

Answer explanation

The variable 'age' is set to 18. The first condition checks if age is less than 13 (false), the second checks if age is between 13 and 17 (false). Thus, it goes to the else block, printing 'Adult', which is the correct answer.

What is the output of the following code? val day = 3 when (day) { 1 -> println("Sunday") 2 -> println("Monday") 3 -> println("Tuesday") else -> println("Invalid day") }

• Monday

• Tuesday

• 3

• Invalid day

Answer explanation

The variable 'day' is set to 3. The 'when' expression checks the value of 'day' and matches it to the case for 3, which prints 'Tuesday'. Therefore, the output of the code is 'Tuesday'.

What is the output of the following code? for (i in 1..5) { if (i == 3) continue if (i == 5) break println(i) }

• 1 2 4

• 1 2

• 1 2 3 4

• 1 2 3 4 5

Answer explanation

The loop iterates from 1 to 5. When i is 3, 'continue' skips the print. When i is 5, 'break' exits the loop. Thus, only 1 and 2 are printed, making '1 2' the correct output.

What is the output of the following code? class Student { var name: String = "" var age: Int = 0 fun displayInfo() { println("Name: $name") println("Age: $age") } } fun main() { val student1 = Student() student1.name = "Rahul" student1.age = 20 student1.displayInfo() }

• Rahul, 20

• Name: Rahul Age: 20

• Name Age

• displayInfo

Answer explanation

The code creates a Student object, sets its name and age, and calls displayInfo(). This method prints the name and age in the format 'Name: Rahul' and 'Age: 20', resulting in 'Name: Rahul Age: 20', which is the correct answer.

What is the output of the following code? val squares = Array(5) { i -> i * i } println(squares.joinToString())

• 1, 4, 9, 16, 25

• 0, 1, 4, 9, 16

• [0, 1, 4, 9, 16]

• Error

Answer explanation

The code creates an array of squares from 0 to 4. The expression 'i -> i * i' computes the square of each index 'i'. Thus, the output is '0, 1, 4, 9, 16', making the correct choice '0, 1, 4, 9, 16'.