Grid container in CSS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a grid container in CSS Grid?

A grid container is an HTML element with display: grid; or display: inline-grid;. It defines a grid layout where its child elements become grid items arranged in rows and columns.

beginner

How do you make an element a grid container?

You set its CSS display property to grid or inline-grid. For example: display: grid;.

beginner

What happens to the children of a grid container?

They become grid items. These items are placed automatically or manually into the grid's rows and columns defined by the container.

intermediate

Which CSS properties define the rows and columns of a grid container?

The properties grid-template-columns and grid-template-rows define the number and size of columns and rows in the grid container.

beginner

Why is using a grid container helpful for web layouts?

It helps organize content in a clean, flexible way using rows and columns. It adapts well to different screen sizes and makes complex layouts easier to build and maintain.

Which CSS property turns an element into a grid container?

A display: grid;

B position: grid;

C float: grid;

D grid-template-columns: 1fr 1fr;

Only display: grid; or display: inline-grid; makes an element a grid container.

What do the children of a grid container become?

A Block elements

B Grid items

C Flex items

D Inline elements

Children of a grid container automatically become grid items.

Which property defines the number and size of columns in a grid container?

A grid-auto-flow

B grid-template-rows

C grid-gap

D grid-template-columns

grid-template-columns sets the columns; grid-template-rows sets the rows.

What is the default display value that creates a grid container?

A block

B inline-grid

C grid

D flex

The default grid container display is grid. inline-grid is also valid but less common.

Why use a grid container instead of floats for layout?

A Grid is easier for rows and columns layout

B Floats are faster

C Grid requires less CSS

D Floats work better on mobile

Grid is designed for two-dimensional layouts with rows and columns, making it easier and more flexible than floats.

Explain what a grid container is and how it affects its child elements.

Think about how setting display changes the children arrangement.

Describe how you would define a grid with three equal columns using a grid container.

Use fractional units to divide space evenly.

Practice

1. What CSS property do you use to make an element a grid container?

easy

A. grid-template-columns: auto;

B. display: flex;

C. position: grid;

D. display: grid;

Solution

1. Step 1: Understand grid container basics

   To create a grid layout, the container must have display: grid; set.

2. Step 2: Check other options

   display: flex; creates a flexbox, not grid. position: grid; is invalid. grid-template-columns defines columns but does not make container a grid.

3. Final Answer:

   display: grid; -> Option D

4. Quick Check:

   Grid container = display: grid; [OK]

Hint: Grid container always needs display: grid; [OK]

Common Mistakes:

• Using display: flex; instead of grid
• Trying to use position: grid;
• Setting grid-template-columns without display: grid;

2. Which of the following is the correct syntax to create a grid with 3 equal columns?

easy

A. grid-template-columns: 1fr 1fr 1fr;

B. grid-template-columns: 3px;

C. grid-columns: repeat(3, 1fr);

D. grid-template-rows: 1fr 1fr 1fr;

Solution

1. Step 1: Understand grid-template-columns syntax

   The property grid-template-columns defines columns. Using 1fr 1fr 1fr creates 3 equal columns.

2. Step 2: Check other options

   3px is a fixed small width, not equal columns. grid-columns is invalid property. grid-template-rows sets rows, not columns.

3. Final Answer:

   grid-template-columns: 1fr 1fr 1fr; -> Option A

4. Quick Check:

   Equal columns = grid-template-columns: 1fr 1fr 1fr; [OK]

Hint: Use grid-template-columns with 1fr units for equal columns [OK]

Common Mistakes:

• Using grid-columns instead of grid-template-columns
• Confusing rows and columns properties
• Using fixed px values for equal flexible columns

3. Given this CSS:

 .container {
  display: grid;
  grid-template-columns: 100px 200px;
  grid-template-rows: 50px 50px;
}

How many grid cells are created inside .container?

medium

A. 4

B. 2

C. 6

D. 8

Solution

1. Step 1: Calculate columns and rows

   There are 2 columns (100px and 200px) and 2 rows (50px and 50px).

2. Step 2: Multiply columns by rows

   Total grid cells = 2 columns x 2 rows = 4 cells.

3. Final Answer:

   4 -> Option A

4. Quick Check:

   2 columns x 2 rows = 4 cells [OK]

Hint: Multiply number of columns by rows for total grid cells [OK]

Common Mistakes:

• Adding columns and rows instead of multiplying
• Counting only columns or only rows
• Confusing grid cells with grid lines

4. What is wrong with this CSS if the goal is to create a grid container with 3 equal columns?

 .grid {
  display: grid;
  grid-template-columns: repeat(3);
}

medium

A. display: grid; is missing

B. Missing unit for repeat count

C. repeat() requires two arguments: count and size

D. grid-template-columns cannot use repeat()

Solution

1. Step 1: Check repeat() syntax

   The repeat() function needs two arguments: number of times and size, e.g. repeat(3, 1fr).

2. Step 2: Identify the error

   Here, only repeat(3) is given, missing the size argument, so it's invalid.

3. Final Answer:

   repeat() requires two arguments: count and size -> Option C

4. Quick Check:

   repeat() needs count and size [OK]

Hint: repeat() always needs count and size, like repeat(3, 1fr) [OK]

Common Mistakes:

• Using repeat() with only one argument
• Forgetting to specify display: grid;
• Thinking repeat() is invalid in grid-template-columns

5. You want a grid container that has 2 columns: the first column is 150px wide, and the second column fills the remaining space. Which CSS is correct?

hard

A. display: grid; grid-template-columns: 150px auto;

B. display: grid; grid-template-columns: 150px 1fr;

C. display: grid; grid-template-columns: auto 150px;

D. display: grid; grid-template-columns: 1fr 150px;

Solution

1. Step 1: Understand fixed and flexible columns

   150px is fixed width. To fill remaining space, use 1fr which means flexible fraction.

2. Step 2: Check options

   display: grid; grid-template-columns: 150px auto; uses auto which sizes based on content, not remaining space. Options B and D put 150px in wrong column order.

3. Final Answer:

   display: grid; grid-template-columns: 150px 1fr; -> Option B

4. Quick Check:

   Fixed + flexible = 150px 1fr [OK]

Hint: Use 1fr for flexible space after fixed width [OK]

Common Mistakes:

• Using auto instead of 1fr for flexible space
• Swapping column order
• Not setting display: grid;