Grid rows and columns in CSS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What CSS property defines the number and size of columns in a grid?

The grid-template-columns property sets the number and size of columns in a CSS grid layout.

beginner

How do you set three rows each 100px tall in a CSS grid?

Use grid-template-rows: 100px 100px 100px; to create three rows each 100 pixels tall.

beginner

What does the CSS value 1fr mean in grid layouts?

1fr means one fraction of the available space. It divides space evenly among grid tracks.

intermediate

How can you create a grid with two columns: first 200px wide, second fills remaining space?

Use grid-template-columns: 200px 1fr;. The first column is fixed 200px, the second takes leftover space.

intermediate

What is the difference between grid-template-rows and grid-auto-rows?

grid-template-rows sets explicit row sizes you define. grid-auto-rows sets size for rows created automatically beyond those defined.

Which CSS property controls the height of grid rows?

A grid-template-rows

B grid-template-columns

C grid-row-gap

D grid-auto-columns

grid-template-rows sets the height of rows in a grid.

What does grid-template-columns: repeat(3, 1fr); do?

A Creates 3 rows each 1fr tall

B Creates 1 column repeated 3 times vertically

C Creates 3 columns each 1px wide

D Creates 3 columns each taking equal space

This creates 3 columns, each sharing equal fraction of available width.

If you want a grid row to be exactly 150 pixels tall, which value do you use?

A 150fr

B 150px

C auto

D 1fr

Using 150px sets a fixed height of 150 pixels.

Which property sets the size of rows created automatically beyond the defined rows?

A grid-row-gap

B grid-template-rows

C grid-auto-rows

D grid-template-columns

grid-auto-rows controls size of implicit rows added by the grid.

What does 1fr represent in grid sizing?

A One fraction of available space

B One fixed pixel

C One percentage

D One em unit

1fr means one fraction of the leftover space in the grid container.

Explain how to create a grid with 4 columns where the first two are 100px wide and the last two share the remaining space equally.

Think about mixing fixed sizes with fractional units.

Describe the difference between explicit and implicit grid rows and how CSS properties control their sizes.

Consider what happens when you add more content than defined rows.

Practice

1. What does the CSS property grid-template-columns control in a grid layout?

easy

A. The number and width of columns in the grid

B. The number and height of rows in the grid

C. The gap between grid items

D. The background color of the grid container

Solution

1. Step 1: Understand the property name

   The property name grid-template-columns suggests it controls columns.

2. Step 2: Recall grid layout basics

   This property sets how many columns there are and their widths.

3. Final Answer:

   The number and width of columns in the grid -> Option A

4. Quick Check:

   grid-template-columns = columns control [OK]

Hint: Columns = grid-template-columns, rows = grid-template-rows [OK]

Common Mistakes:

• Confusing columns with rows
• Thinking it controls gaps
• Mixing it with background styles

2. Which of the following is the correct syntax to create a grid with 3 columns each 100px wide?

easy

A. grid-template-columns: repeat(3, 100px);

B. grid-template-columns: 3x 100px;

C. grid-template-columns: 100px, 100px, 100px;

D. grid-template-columns: 100px * 3;

Solution

1. Step 1: Identify valid CSS syntax for repeating columns

   The repeat() function is the correct way to repeat values in grid-template-columns.

2. Step 2: Check each option

   grid-template-columns: 100px, 100px, 100px; uses commas (invalid); B: '3x 100px' invalid; C: repeat(3, 100px) correct; D: '* 3' invalid CSS syntax.

3. Final Answer:

   grid-template-columns: repeat(3, 100px); -> Option A

4. Quick Check:

   Use repeat() for repeating columns [OK]

Hint: Use repeat() to simplify repeated column sizes [OK]

Common Mistakes:

• Writing invalid CSS like '3x 100px'
• Using commas between column sizes
• Using multiplication syntax not supported in CSS

3. Given the CSS below, how many rows and columns will the grid have?

display: grid;
grid-template-columns: 150px 1fr 2fr;
grid-template-rows: 100px auto;

medium

A. 2 columns and 2 rows

B. 2 columns and 3 rows

C. 3 columns and 3 rows

D. 3 columns and 2 rows

Solution

1. Step 1: Count columns from grid-template-columns

   There are three values: 150px, 1fr, 2fr, so 3 columns.

2. Step 2: Count rows from grid-template-rows

   There are two values: 100px and auto, so 2 rows.

3. Final Answer:

   3 columns and 2 rows -> Option D

4. Quick Check:

   Count values in columns and rows properties [OK]

Hint: Count values in grid-template-columns and grid-template-rows [OK]

Common Mistakes:

• Mixing up rows and columns count
• Assuming 'auto' adds extra rows
• Ignoring fractional units

4. Identify the error in this CSS grid code:

display: grid;
grid-template-columns: 100px, 200px, 100px;
grid-template-rows: 50px 50px;

medium

A. grid-template-rows must have commas between values

B. Commas should not be used between column sizes

C. display: grid; should be display: grid-container;

D. Column sizes must all be the same unit

Solution

1. Step 1: Check syntax for grid-template-columns

   Values should be space-separated, not comma-separated.

2. Step 2: Verify other options

   grid-template-rows is correct without commas; display: grid is valid; units can differ.

3. Final Answer:

   Commas should not be used between column sizes -> Option B

4. Quick Check:

   Grid values are space-separated, not comma-separated [OK]

Hint: Use spaces, not commas, between grid sizes [OK]

Common Mistakes:

• Using commas between grid sizes
• Changing display property incorrectly
• Thinking units must match

5. You want a grid with 4 equal columns and 3 rows where the first row is 100px tall and the others share remaining space equally. Which CSS is correct?

hard

A. grid-template-columns: repeat(3, 1fr); grid-template-rows: 100px 1fr 1fr 1fr;

B. grid-template-columns: 4fr; grid-template-rows: 100px auto auto;

C. grid-template-columns: repeat(4, 1fr); grid-template-rows: 100px 1fr 1fr;

D. grid-template-columns: 1fr 1fr 1fr 1fr; grid-template-rows: 100px 100px 100px;

Solution

1. Step 1: Set 4 equal columns

   Using repeat(4, 1fr) creates 4 columns each taking equal space.

2. Step 2: Define 3 rows with first fixed and others flexible

   grid-template-rows: 100px 1fr 1fr; sets first row fixed 100px, next two share remaining space equally.

3. Final Answer:

   grid-template-columns: repeat(4, 1fr); grid-template-rows: 100px 1fr 1fr; -> Option C

4. Quick Check:

   repeat() for columns, fixed + fractional rows [OK]

Hint: Use repeat() for equal columns and 1fr for flexible rows [OK]

Common Mistakes:

• Wrong number of columns or rows
• Using auto instead of 1fr for equal space
• Setting all rows fixed height