Why string handling matters in Kotlin - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print the length of the string.

Kotlin

val text = "Hello, Kotlin!"
println(text.[1])

Drag options to blanks, or click blank then click option'

Asize

Blength()

Ccount

Dlength

Attempts:

3 left

💡 Hint

Common Mistakes

Using length() with parentheses causes an error because length is a property, not a function.

In Kotlin, length is a property of the String class that gives the number of characters.

2fill in blank

medium

Complete the code to convert the string to uppercase.

Kotlin

val greeting = "hello"
val shout = greeting.[1]()

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Auppercase

BtoUpperCase

CtoLowerCase

DupperCase

Attempts:

3 left

💡 Hint

Common Mistakes

Using toUpperCase() which is deprecated in Kotlin 1.5+.

Using upperCase() which is not a valid function.

The correct function in Kotlin to convert a string to uppercase is uppercase().

3fill in blank

hard

Fix the error in the code to check if the string starts with "Hi".

Kotlin

val message = "Hi there!"
val starts = message.[1]("Hi")

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AbeginWith

BstartsWith

Cstarts

DstartWith

Attempts:

3 left

💡 Hint

Common Mistakes

Misspelling the function name causes a compilation error.

The correct function to check the start of a string is startsWith().

4fill in blank

hard

Fill both blanks to create a map of words to their lengths for words longer than 3 characters.

Kotlin

val words = listOf("apple", "bat", "car", "door")
val lengths = words.associateWith { it.[1] }.filter { it.value [2] 3 }

Drag options to blanks, or click blank then click option'

Alength

B>

C<

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Using < instead of > causes filtering of shorter words instead.

Using count() instead of length property causes an error.

Use length to get the word length and > to filter words longer than 3 characters.

5fill in blank

hard

Fill all three blanks to create a map of uppercase words to their lengths for words containing 'a'.

Kotlin

val words = listOf("apple", "bat", "car", "door")
val result = words.filter { it.[1]('a') }.associate { it.[2]() to it.[3] }

Drag options to blanks, or click blank then click option'

Acontains

Buppercase

Clength

DstartsWith

Attempts:

3 left

💡 Hint

Common Mistakes

Using startsWith instead of contains misses words with 'a' not at start.

Forgetting parentheses on uppercase() causes errors.

Use contains to check for 'a', uppercase() to convert words, and length for their lengths.