Char type and Unicode behavior in Kotlin - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Kotlin code with Char arithmetic?

Consider the following Kotlin code snippet. What will it print?

Kotlin

fun main() {
    val c: Char = 'A'
    val result = c + 2
    println(result)
}

A 67

B C

C Error: Operator '+' cannot be applied to 'Char' and 'Int'

D B

💡 Hint

Remember that Char plus Int results in an Int in Kotlin.

In Kotlin, adding an Int to a Char results in an Int representing the Unicode code point sum. 'A' has code 65, plus 2 is 67.

❓ Predict Output

intermediate

What does this Kotlin code print when converting Char to Int?

What is the output of this Kotlin program?

Kotlin

fun main() {
    val ch: Char = '\u03A9' // Greek capital letter Omega
    println(ch.code)
}

A 937

B Omega

C Error: 'code' property not found

D 0x03A9

💡 Hint

The 'code' property returns the Unicode code point as an Int.

The Unicode code point for Greek capital letter Omega (Ω) is 937 decimal.

❓ Predict Output

advanced

What is the output of this Kotlin code using Char ranges and contains?

Analyze the code and select the correct output.

Kotlin

fun main() {
    val vowels = 'a'..'u'
    println('e' in vowels)
    println('z' in vowels)
}

A

false
false

B

false
true

C

true
true

D

true
false

💡 Hint

Check if 'e' and 'z' fall within the range from 'a' to 'u'.

The range 'a'..'u' includes letters from 'a' to 'u'. 'e' is inside, 'z' is outside.

❓ Predict Output

advanced

What error does this Kotlin code raise when converting a Char to Int incorrectly?

What error will this code produce?

Kotlin

fun main() {
    val ch: Char = '1'
    val num: Int = ch
    println(num)
}

A Prints 1

B Prints 49

C Type mismatch: inferred type is Char but Int was expected

D No output, infinite loop

💡 Hint

Kotlin does not allow implicit conversion from Char to Int.

You cannot assign a Char directly to an Int variable without explicit conversion.

🧠 Conceptual

expert

How many characters are in this Kotlin string containing Unicode surrogate pairs?

Consider this Kotlin code snippet. How many characters does the string contain?

Kotlin

fun main() {
    val s = "\uD83D\uDE00" // Unicode emoji 😀 represented as surrogate pair
    println(s.length)
}

A 1

B 2

C 0

D Error at runtime

💡 Hint

Kotlin strings use UTF-16 encoding; surrogate pairs count as two chars.

The emoji 😀 is represented by two UTF-16 code units (surrogate pair), so length is 2.