String to number conversion in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to convert the string "123" to an integer.

Kotlin

val number = "123".[1]()

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

AtoString

BtoDouble

CtoInt

DtoChar

Attempts:

3 left

💡 Hint

Common Mistakes

Using toString() which returns the same string.

Using toDouble() which converts to a floating number.

Using toChar() which converts to a single character.

The toInt() function converts a string to an integer in Kotlin.

2fill in blank

medium

Complete the code to convert the string "45.67" to a double number.

Kotlin

val decimalNumber = "45.67".[1]()

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

AtoDouble

BtoInt

CtoFloat

DtoLong

Attempts:

3 left

💡 Hint

Common Mistakes

Using toInt() which removes decimals.

Using toLong() which converts to a long integer.

Using toFloat() which converts to a float but not double.

The toDouble() function converts a string to a double-precision floating point number.

3fill in blank

hard

Fix the error in the code to safely convert a string to an integer without crashing.

Kotlin

val input = "abc"
val number = input.[1]() ?: 0

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

AtoInt

BtoLong

CtoDouble

DtoIntOrNull

Attempts:

3 left

💡 Hint

Common Mistakes

Using toInt() which throws an exception on invalid input.

Using toDouble() which is not for integers.

Using toLong() which is for long integers.

toIntOrNull() tries to convert the string to an integer and returns null if it fails, avoiding a crash.

4fill in blank

hard

Fill both blanks to create a map of words to their lengths, but only include words longer than 3 characters.

Kotlin

val words = listOf("cat", "house", "tree", "a")
val lengths = words.associateWith { it.[1] }.filter { it.value [2] 3 }

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

Alength

Bcount

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using count() which requires a predicate argument like count { true }.

Using '<' instead of '>' which filters shorter words.

Using length() with parentheses since length is a property, not a function.

The length property returns the number of characters in the string, and > filters words longer than 3.

5fill in blank

hard

Fill all three blanks to create a map of uppercase words to their integer lengths, only for words with length greater than 2.

Kotlin

val words = listOf("dog", "cat", "a", "bird")
val result = words.filter { it.[1] [2] 2 }.associate { it.[3]() to it.length }

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

Alength

B>

Cuppercase

Dlowercase

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'uppercase' without parentheses.

Using '<' instead of '>' in the filter.

Using 'length()' as a function instead of property.

length gets the word length, > filters words longer than 2, and uppercase() converts words to uppercase keys.