If-else expression assignment in Kotlin - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Kotlin code using if-else expression assignment?

Consider the following Kotlin code snippet:

val x = 10
val result = if (x > 5) "Greater" else "Smaller or equal"
println(result)

What will be printed?

Kotlin

val x = 10
val result = if (x > 5) "Greater" else "Smaller or equal"
println(result)

A Greater

B Smaller or equal

C Compilation error

D 10

💡 Hint

Remember that if-else in Kotlin can be used as an expression that returns a value.

The variable result is assigned the value of the if-else expression. Since x is 10, which is greater than 5, the expression returns "Greater".

❓ Predict Output

intermediate

What is the value of 'message' after this Kotlin code runs?

Look at this Kotlin code:

val number = 3
val message = if (number % 2 == 0) "Even" else "Odd"
println(message)

What will be printed?

Kotlin

val number = 3
val message = if (number % 2 == 0) "Even" else "Odd"
println(message)

A Even

B Runtime exception

C 3

D Odd

💡 Hint

Check the condition for even numbers using modulo operator.

The number 3 is not divisible by 2, so the else branch "Odd" is assigned to message.

❓ Predict Output

advanced

What does this Kotlin code print when using nested if-else expressions?

Analyze this Kotlin snippet:

val score = 75
val grade = if (score >= 90) "A"
            else if (score >= 80) "B"
            else if (score >= 70) "C"
            else "F"
println(grade)

What is the output?

Kotlin

val score = 75
val grade = if (score >= 90) "A"
            else if (score >= 80) "B"
            else if (score >= 70) "C"
            else "F"
println(grade)

A A

B B

C C

D F

💡 Hint

Check each condition in order from top to bottom.

The score 75 is less than 80 but greater or equal to 70, so the third condition is true and "C" is assigned.

❓ Predict Output

advanced

What error does this Kotlin code produce?

Consider this Kotlin code snippet:

val x = 5
val y = if x > 3 "Yes" else "No"
println(y)

What error will occur?

Kotlin

val x = 5
val y = if x > 3 "Yes" else "No"
println(y)

A SyntaxError: Missing parentheses in if condition

B TypeError: Cannot assign String to Int

C No error, prints "Yes"

D RuntimeException: Null pointer

💡 Hint

Check the syntax of the if expression in Kotlin.

Kotlin requires parentheses around the condition in an if expression. Missing parentheses cause a syntax error.

🧠 Conceptual

expert

How many items are in the resulting list after this Kotlin code runs?

Examine this Kotlin code:

val numbers = listOf(1, 2, 3, 4, 5)
val results = numbers.map { if (it % 2 == 0) it * 2 else it * 3 }
println(results.size)

How many items does results contain?

Kotlin

val numbers = listOf(1, 2, 3, 4, 5)
val results = numbers.map { if (it % 2 == 0) it * 2 else it * 3 }
println(results.size)

A 2

B 5

C 3

D 0

💡 Hint

Remember that map transforms each item but keeps the list size.

The map function applies the if-else expression to each of the 5 items, so the resulting list has 5 items.