LazyRow for horizontal lists in Android Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is LazyRow in Jetpack Compose?

LazyRow is a composable that displays a horizontally scrolling list. It only composes and lays out visible items, improving performance for long lists.

beginner

How do you add spacing between items in a LazyRow?

You can add spacing by using the horizontalArrangement parameter with Arrangement.spacedBy(dp) to set space between items.

intermediate

Why use LazyRow instead of Row for horizontal lists?

LazyRow only creates items that are visible on screen, saving memory and CPU. Row creates all items at once, which can be slow and use more memory for large lists.

beginner

How do you handle item clicks inside a LazyRow?

You wrap each item in a clickable modifier like Modifier.clickable { /* handle click */ } to respond to user taps.

beginner

What parameter do you use to provide the list of items to LazyRow?

You use the items function inside LazyRow's content block to pass a list and define how each item looks.

What does LazyRow do in Jetpack Compose?

A Displays a horizontally scrolling list with lazy loading

B Displays a vertical list of items

C Creates all items at once in a horizontal layout

D Is used for navigation between screens

LazyRow shows a horizontal list and only composes visible items for better performance.

How can you add space between items in a LazyRow?

A Use verticalArrangement = Arrangement.spacedBy(dp)

B Use padding inside each item only

C Use horizontalArrangement = Arrangement.spacedBy(dp)

D Use Modifier.fillMaxWidth()

horizontalArrangement controls spacing between items horizontally in LazyRow.

Which modifier allows an item in LazyRow to respond to taps?

A Modifier.clickable()

B Modifier.background()

C Modifier.fillMaxSize()

D Modifier.padding()

Modifier.clickable() makes an item respond to user clicks.

Why is LazyRow preferred over Row for long horizontal lists?

A Row supports lazy loading

B LazyRow creates all items at once

C LazyRow scrolls vertically

D LazyRow only composes visible items, improving performance

LazyRow improves performance by only composing visible items.

How do you provide data items to LazyRow?

A Passing a list to LazyColumn

B Using the items() function inside LazyRow

C Using a for loop inside Row

D Using setContentView()

items() inside LazyRow lets you pass a list and define each item's UI.

Explain how LazyRow improves performance compared to a regular Row when displaying many items horizontally.

Think about how many items are created and drawn on screen.

Describe how you would add clickable behavior and spacing between items in a LazyRow.

Consider modifiers and LazyRow parameters.