Column and Row layouts in Android Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Column layout in Android Compose?

A Column layout arranges its child components vertically, one below the other, like stacking books on a shelf.

beginner

What is a Row layout in Android Compose?

A Row layout arranges its child components horizontally, side by side, like people standing in a line.

intermediate

How do you add space between items in a Column or Row?

You can use the verticalArrangement for Column or horizontalArrangement for Row with values like Arrangement.spacedBy(8.dp) to add space between items.

beginner

What does Modifier.fillMaxWidth() do in a Row layout?

It makes the Row stretch to fill the entire width of its parent container, like spreading your arms wide to cover the space.

intermediate

Why use Modifier.weight() in Row or Column?

It lets child components share available space proportionally, like dividing a pizza into slices based on appetite.

Which layout arranges children vertically in Android Compose?

A Row

B Column

C Box

D Stack

Column arranges children vertically, one below another.

How do you add horizontal space between items in a Row?

A horizontalArrangement = Arrangement.spacedBy()

B weight() modifier

C padding() modifier

D verticalArrangement = Arrangement.spacedBy()

horizontalArrangement controls spacing between Row children.

What does Modifier.fillMaxWidth() do in a Column?

A Centers Column content

B Makes Column fill parent's height

C Adds padding inside Column

D Makes Column fill parent's width

fillMaxWidth() makes the layout fill the full width available.

Which modifier helps children share space proportionally in Row or Column?

A weight()

B padding()

C fillMaxSize()

D background()

weight() divides space among children based on assigned weights.

If you want to stack items horizontally, which layout do you use?

A Column

B Box

C Row

D Spacer

Row arranges items side by side horizontally.

Explain how Column and Row layouts differ and when you would use each.

Think about stacking books vs lining up people.

Describe how to add space between items in a Column or Row layout in Compose.

Spacing is like leaving gaps between objects on a shelf or in a line.

Practice

1. Which layout arranges its child views vertically in Android Kotlin?

easy

A. Row

B. Column

C. Grid

D. FrameLayout

Solution

1. Step 1: Understand layout orientation

   Column arranges children vertically, stacking them top to bottom.

2. Step 2: Compare with other layouts

   Row arranges children horizontally, Grid arranges in a grid, FrameLayout stacks overlapping.

3. Final Answer:

   Column -> Option B

4. Quick Check:

   Vertical arrangement = Column [OK]

Hint: Vertical means top to bottom, so use Column [OK]

Common Mistakes:

• Confusing Row with Column
• Thinking Grid arranges vertically only
• Mixing FrameLayout stacking with vertical layout

2. Which of the following is the correct Kotlin syntax to create a Row layout with two Text views inside?

easy

A. Row(
Text("Hello"),
Text("World")
)

B. Column {
Text("Hello")
Text("World")
}

C. Row {
Text("Hello")
Text("World")
}

D. Row {
TextView("Hello")
TextView("World")
}

Solution

1. Step 1: Identify correct Row syntax

   Row uses curly braces with child composables inside, separated by lines.

2. Step 2: Check child components

   Text is the correct composable for text display, TextView is Android View, not Compose.

3. Final Answer:

   Row { Text("Hello") Text("World") } -> Option C

4. Quick Check:

   Row uses braces and Text composables [OK]

Hint: Use braces {} for layouts and Text composable for text [OK]

Common Mistakes:

• Using parentheses instead of braces for Row
• Using Column instead of Row
• Using TextView instead of Text composable

3. What will be the visual arrangement of the following code?

Column {
  Text("A")
  Row {
    Text("B")
    Text("C")
  }
  Text("D")
}

medium

A. A at top, B and C side by side in middle, D at bottom vertically

B. A, B, C, D all side by side horizontally

C. A, B, C stacked vertically, D missing

D. Only A and D visible, B and C hidden

Solution

1. Step 1: Analyze outer Column layout

   Column stacks children vertically: Text("A"), then Row, then Text("D").

2. Step 2: Analyze inner Row layout

   Row arranges Text("B") and Text("C") horizontally side by side.

3. Final Answer:

   A at top, B and C side by side in middle, D at bottom vertically -> Option A

4. Quick Check:

   Column vertical + Row horizontal = mixed layout [OK]

Hint: Column stacks vertically, Row stacks horizontally inside [OK]

Common Mistakes:

• Thinking Row inside Column stacks vertically
• Ignoring inner Row layout
• Assuming all texts are horizontal

4. Identify the error in this Kotlin Compose code snippet:

Row {
  Text("Hello")
  Text("World")
  Column(
    Text("Nested")
  )
}

medium

A. Missing comma between Text("Hello") and Text("World")

B. Text composable cannot be inside Column

C. Row cannot contain Column as child

D. Column should use braces {} instead of parentheses ()

Solution

1. Step 1: Check Column syntax

   Column uses curly braces {} to enclose children, not parentheses ().

2. Step 2: Verify child composables

   Text can be inside Column; Row can contain Column; commas are not needed between children.

3. Final Answer:

   Column should use braces {} instead of parentheses () -> Option D

4. Quick Check:

   Layouts use braces {} for children [OK]

Hint: Use {} for layout children, not () [OK]

Common Mistakes:

• Using () instead of {} for layouts
• Thinking commas are required between children
• Believing nested layouts are not allowed

5. You want to create a UI where three buttons are arranged horizontally, but the middle button should be twice as wide as the others. Which layout and modifier approach is best in Kotlin Compose?

hard

A. Use Row with weights: Button1 weight=1, Button2 weight=2, Button3 weight=1

B. Use Column with padding on middle button

C. Use Row with fixed width buttons and margin on middle button

D. Use Column with weight modifiers on buttons

Solution

1. Step 1: Choose horizontal layout

   Row arranges children horizontally, perfect for side-by-side buttons.

2. Step 2: Use weight modifier for sizing

   Assign weights to buttons to control relative widths; middle button weight=2 makes it twice as wide.

3. Final Answer:

   Use Row with weights: Button1 weight=1, Button2 weight=2, Button3 weight=1 -> Option A

4. Quick Check:

   Row + weights control horizontal size [OK]

Hint: Use Row and weight modifiers for proportional widths [OK]

Common Mistakes:

• Using Column for horizontal arrangement
• Using fixed widths instead of weights
• Applying padding instead of weight for size