Range operator (..) and in operator in Kotlin - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of range and in operator with characters

What is the output of this Kotlin code snippet?

Kotlin

val result = 'c' in 'a'..'f'
println(result)

A false

B Compilation error

C Runtime exception

D true

💡 Hint

Check if the character 'c' lies between 'a' and 'f' inclusive.

The range 'a'..'f' includes all characters from 'a' to 'f'. Since 'c' is within this range, the expression returns true.

❓ Predict Output

intermediate

Range operator with integers and in operator

What will be printed by this Kotlin code?

Kotlin

val x = 10
val isInRange = x in 1..10
println(isInRange)

A true

B false

C Compilation error

D Runtime exception

💡 Hint

Remember the range 1..10 includes both 1 and 10.

The number 10 is included in the range 1..10, so x in 1..10 evaluates to true.

❓ Predict Output

advanced

Output of reversed range with in operator

What is the output of this Kotlin code?

Kotlin

val num = 5
val range = 10 downTo 1
println(num in range)

A false

B true

C Compilation error

D Runtime exception

💡 Hint

Check if 5 is within the range from 10 down to 1.

The downTo operator creates a decreasing range from 10 to 1. Since 5 is between 10 and 1, num in range is true.

❓ Predict Output

advanced

Checking if a value is in a step range

What will this Kotlin code print?

Kotlin

val range = 1..10 step 3
println(7 in range)

A Compilation error

B true

C false

D Runtime exception

💡 Hint

The range includes numbers 1, 4, 7, 10 or not?

The range 1..10 step 3 includes 1, 4, 7, and 10. However, the in operator checks for containment based on the step sequence. Since 7 is included in the stepped range, the output should be true. But in Kotlin, the in operator with stepped ranges checks for exact matches in the progression. Actually, 7 is included, so the output is true.

❓ Predict Output

expert

Output of complex range and in operator with floating point

What is the output of this Kotlin code snippet?

Kotlin

val x = 3.5
val range = 1.0..5.0
println(x in range)

A Compilation error

B false

C Runtime exception

D true

💡 Hint

Check if the range operator (..) works with Double type in Kotlin.

The range operator (..) in Kotlin does not support floating point types like Double. This code will not compile because 1.0..5.0 is invalid.