If as an expression returning value in Kotlin - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Kotlin code using if as an expression?

Consider the following Kotlin code snippet. What will be printed when it runs?

Kotlin

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

A true

B Smaller or equal

C Greater

D 10

💡 Hint

Remember that in Kotlin, if can return a value that you can assign to a variable.

The if expression checks if x is greater than 5. Since 10 is greater than 5, it returns "Greater" which is assigned to result and printed.

❓ Predict Output

intermediate

What value does the variable 'message' hold after this code runs?

Look at this Kotlin code. What is the value of 'message' after execution?

Kotlin

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

A 3

B Odd

C Even

D true

💡 Hint

Check if the number is divisible by 2 without remainder.

3 % 2 equals 1, which is not zero, so the else branch "Odd" is assigned to message.

🧠 Conceptual

advanced

Which Kotlin code snippet correctly uses if as an expression to assign a value?

Select the option that correctly uses if as an expression returning a value in Kotlin.

A val result = if (a > b) a else b

B val result = if a > b { a } else { b }

C val result = if (a > b) { a } else

D val result = if (a > b) a; else b

💡 Hint

Remember the syntax for if expressions requires parentheses and else branch.

Option A correctly uses if as an expression with parentheses and else branch returning values. Other options have syntax errors.

❓ Predict Output

advanced

What is the output of this Kotlin code using nested if expressions?

Analyze the code and choose the output printed.

Kotlin

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

A C

B B

C F

D A

💡 Hint

Check each condition from top to bottom to see which one matches first.

Score 75 is not >= 90 or 80 but is >= 70, so the grade is "C".

❓ Predict Output

expert

What is the output of this Kotlin code using if expression with side effects?

Consider this Kotlin code. What will be printed when it runs?

Kotlin

fun main() {
    var count = 0
    val result = if (++count > 0) {
        "Positive"
    } else {
        "Non-positive"
    }
    println("count = $count, result = $result")
}

A count = 0, result = Non-positive

B count = 0, result = Positive

C count = 1, result = Non-positive

D count = 1, result = Positive

💡 Hint

Remember that ++count increments before comparison.

++count increments count from 0 to 1 before comparison, so condition is true and result is "Positive".