Also function behavior and use cases in Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the also function in Kotlin?

The also function lets you perform additional actions on an object without changing it. It returns the original object after running the given block.

intermediate

How does also differ from apply in Kotlin?

also passes the object as it and returns the original object, mainly for side effects. apply uses this and is often used to configure an object.

beginner

Show a simple example of using also to log a value during a chain of calls.

val result = "Hello".also { println("Logging: $it") }.uppercase() // Prints: Logging: Hello // result = "HELLO"

beginner

When is it useful to use also in Kotlin?

Use also when you want to do something extra with an object (like logging, debugging, or validation) without changing the object or breaking a chain of calls.

beginner

What does also return after executing its block?

also always returns the original object it was called on, regardless of what happens inside the block.

What does the also function return in Kotlin?

A The original object it was called on

B The result of the block inside <code>also</code>

C A new object created inside the block

D Null

also returns the original object after executing the block.

In the also function, how is the object passed to the block?

A As <code>this</code>

B As <code>it</code>

C As a parameter named <code>obj</code>

D It is not passed

The object is passed as it inside the also block.

Which of these is a common use case for also?

A Changing the object’s properties

B Returning a different object

C Performing side effects like logging

D Creating a new object

also is often used for side effects such as logging or debugging.

How does also help in method chaining?

A It breaks the chain by returning null

B It modifies the object and returns a new one

C It stops the chain and returns a Boolean

D It allows side effects without breaking the chain

also lets you do extra work without breaking the chain because it returns the original object.

Which keyword is used inside the also block to refer to the object?

A it

B self

C this

D obj

Inside also, the object is referenced as it.

Explain how the also function works in Kotlin and give an example of when you might use it.

Think about doing something extra without changing the object.

Compare also and apply in Kotlin. When would you choose one over the other?

Focus on how the object is referenced and what you want to do with it.