@import to @use migration in SASS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main difference between @import and @use in Sass?

@import includes styles multiple times and can cause conflicts. @use loads styles once and keeps them in a namespace to avoid conflicts.

beginner

How do you replace <code>@import 'colors';</code> with <code>@use</code>?

Use @use 'colors'; instead. This loads the colors file once and requires you to prefix variables or mixins with colors..

intermediate

Why does @use help avoid variable conflicts?

Because @use creates a namespace for the imported file. You must write namespace.$variable, so variables with the same name in different files don’t clash.

intermediate

How can you shorten the namespace when using @use?

You can add as * to @use like @use 'colors' as *; to use variables without the namespace prefix, but use it carefully to avoid conflicts.

intermediate

What should you do if you want to share variables or mixins globally with @use?

Create a separate file for shared variables and @use it in each file that needs them. This keeps your code organized and avoids duplication.

Which Sass directive loads a file only once and uses namespaces?

A @use

B @import

C @forward

D @mixin

@use loads a file once and creates a namespace to avoid conflicts.

How do you access a variable named $color from a file loaded with @use 'theme';?

A $color

B theme.color

C theme.$color

D theme.$color()

You must prefix the variable with the namespace: theme.$color.

What does @use 'colors' as *; do?

A Imports colors with the namespace 'colors'

B Imports colors without any namespace

C Imports colors multiple times

D Imports colors as a mixin

Using as * removes the namespace, so you can use variables directly.

Why should you avoid using @import in new Sass projects?

A It is required for variables

B It is faster than @use

C It supports namespaces

D It is deprecated and can cause duplicate styles

@import is deprecated and can cause duplicate styles and conflicts.

Which directive allows you to re-export styles from one file to another in Sass?

A @forward

B @use

C @import

D @mixin

@forward lets you re-export styles from one file to another.

Explain how to migrate a Sass project from using @import to @use. What are the key steps and benefits?

Think about how @use changes the way you access variables and why it is better.

Describe how namespaces work in Sass when using @use. Why are they important?

Consider how multiple files can have the same variable names.

Practice

1. What is the main advantage of using @use instead of @import in Sass?

easy

A. It allows importing CSS files directly without processing.

B. It loads files only once and uses namespaces to avoid conflicts.

C. It automatically compiles Sass to CSS without a compiler.

D. It enables inline JavaScript execution inside Sass files.

Solution

1. Step 1: Understand @import behavior

   @import loads files multiple times and merges all variables globally, which can cause conflicts.

2. Step 2: Understand @use improvements

   @use loads files only once and requires a namespace prefix, preventing variable and mixin conflicts.

3. Final Answer:

   It loads files only once and uses namespaces to avoid conflicts. -> Option B

4. Quick Check:

   @use = safer, namespaced imports [OK]

Hint: Remember: @use loads once with namespaces [OK]

Common Mistakes:

• Thinking @use imports CSS files directly
• Assuming @use runs JavaScript
• Believing @use compiles Sass automatically

2. Which of the following is the correct syntax to replace @import 'colors'; with @use and a namespace c?

easy

A. @use 'colors' as c;

B. @use colors as 'c';

C. @use 'colors' namespace c;

D. @use 'colors' with c;

Solution

1. Step 1: Recall @use syntax

   The correct syntax is @use 'filename' as namespace; with quotes around filename and as keyword.

2. Step 2: Match options

   @use 'colors' as c; matches the correct syntax exactly: @use 'colors' as c;.

3. Final Answer:

   @use 'colors' as c; -> Option A

4. Quick Check:

   Correct @use syntax = @use 'colors' as c; [OK]

Hint: Use quotes and 'as' keyword for namespace [OK]

Common Mistakes:

• Omitting quotes around filename
• Using 'namespace' instead of 'as'
• Placing namespace inside quotes

3. Given the Sass files:

// _variables.scss
$primary-color: blue;

// styles.scss
@use 'variables' as vars;
.button {
  color: vars.$primary-color;
}

What color will the button text be in the compiled CSS?

medium

A. blue

B. vars.$primary-color

C. undefined

D. red

Solution

1. Step 1: Understand variable access with @use

   The variable $primary-color is accessed with the namespace prefix vars.$primary-color.

2. Step 2: Check variable value

   In _variables.scss, $primary-color is set to blue, so the button color will be blue.

3. Final Answer:

   blue -> Option A

4. Quick Check:

   Namespace prefix accesses variable value correctly [OK]

Hint: Use namespace prefix to get variable value [OK]

Common Mistakes:

• Using variable without namespace prefix
• Expecting variable name as string output
• Assuming default color red

4. What is wrong with this Sass code after migrating from @import to @use?

@use 'mixins';
.button {
  @include border-radius(5px);
}

medium

A. Cannot use @include with @use.

B. Incorrect quotes around filename in @use.

C. Missing namespace prefix before border-radius mixin.

D. Mixin name should be borderRadius instead.

Solution

1. Step 1: Understand @use namespace requirement

   When using @use, all variables and mixins must be accessed with the namespace prefix unless configured otherwise.

2. Step 2: Identify missing prefix

   The code calls @include border-radius(5px); without prefix. It should be @include mixins.border-radius(5px);.

3. Final Answer:

   Missing namespace prefix before border-radius mixin. -> Option C

4. Quick Check:

   @use requires namespace prefix [OK]

Hint: Add namespace prefix to mixin calls [OK]

Common Mistakes:

• Calling mixins without namespace prefix
• Confusing quotes usage in @use
• Thinking @include is disallowed

5. You have two Sass files:

// _colors.scss
$primary: red;

// _theme.scss
@use 'colors' as c;
$primary: blue !default;

// styles.scss
@use 'theme' as t;
.button {
  color: t.$primary;
}

What color will the button text be and why?

hard

A. blue, because $primary in theme overrides colors with !default.

B. blue, because @use merges variables without namespaces.

C. red, because !default prevents override in theme.

D. red, because $primary in colors overrides !default in theme.

Solution

1. Step 1: Understand !default behavior

   The !default flag sets a variable only if it is not already set.

2. Step 2: Analyze variable values

   $primary in colors is red. In theme, $primary is set to blue !default, so it will only be set if $primary was not already set.

3. Step 3: Check namespaces and usage

   theme uses colors as c, so $primary from colors is already set. Therefore, blue !default does not override red.

4. Final Answer:

   red, because $primary in colors overrides !default in theme. -> Option D

5. Quick Check:

   !default only sets if variable is unset, so red stays [OK]

Hint: Remember !default sets only if variable is unset [OK]

Common Mistakes:

• Assuming !default always overrides
• Ignoring namespaces in variable access
• Thinking variables merge without prefixes