Lambda syntax and declaration in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a lambda that adds two integers.

Kotlin

val sum: (Int, Int) -> Int = [1]

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

A(a, b) -> a + b

B{ a, b -> a + b }

Cfun(a: Int, b: Int) = a + b

Dlambda(a, b) { a + b }

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses instead of curly braces for lambda declaration.

Trying to use 'fun' keyword inside lambda assignment.

Using incorrect lambda syntax like 'lambda(...)'.

In Kotlin, lambdas are declared with curly braces and parameters before the arrow.

2fill in blank

medium

Complete the code to declare a lambda that returns the length of a string.

Kotlin

val length: (String) -> Int = [1]

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

Afun(s: String) = s.length

B(s) -> s.length

C{ s -> s.length }

Dlambda(s) { s.length }

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses instead of curly braces.

Trying to declare lambda with 'fun' keyword.

Using incorrect lambda syntax like 'lambda(...)'.

Lambda syntax uses curly braces with parameters and arrow before the expression.

3fill in blank

hard

Fix the error in the lambda declaration that multiplies two numbers.

Kotlin

val multiply: (Int, Int) -> Int = [1]

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

A(a, b) -> a * b

Blambda(a, b) { a * b }

Cfun(a: Int, b: Int) = a * b

D{ a, b -> a * b }

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses instead of curly braces for lambda.

Trying to use 'fun' keyword inside lambda assignment.

Using 'lambda' keyword which is not valid in Kotlin.

Kotlin lambdas require curly braces with parameters and arrow inside.

4fill in blank

hard

Fill both blanks to declare a lambda that checks if a number is even.

Kotlin

val isEven: (Int) -> Boolean = { num [1] num [2] 2 == 0 }

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

A%

B==

C*

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using '*' or '+' instead of '%' for remainder.

Using '=' instead of '==' for comparison.

The lambda uses modulo operator '%' to check remainder and '==' to compare with zero.

5fill in blank

hard

Fill all three blanks to create a lambda that filters a list of strings by length greater than 3.

Kotlin

val filtered = words.filter { [1] -> [2].length [3] 3 }

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

Aword

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' for comparison.

Using different parameter names inconsistently.

The lambda parameter is 'word', and it checks if word.length is greater than 3.