Importing built-in modules with @use in SASS - Practice Problems & Coding Challenges

Challenge - 5 Problems

📝 Syntax

intermediate

What is the output of this Sass code using @use?

Consider the following Sass code snippet:

@use "sass:color";

.button {
  color: color.scale(#6699cc, $lightness: 20%);
}

What CSS color value will be generated for the .button class?

SASS

@use "sass:color";

.button {
  color: color.scale(#6699cc, $lightness: 20%);
}

A color: #6699cc;

B color: #336699;

C color: #99bbee;

D color: #99ccff;

💡 Hint

The color.scale function adjusts the lightness of the base color by the given percentage.

The base color #6699cc is lightened by 20%, resulting in a lighter blue shade #99bbee.

🧠 Conceptual

intermediate

Which statement about @use importing built-in Sass modules is true?

Select the correct statement about using the @use rule to import built-in Sass modules like sass:math or sass:color.

A Built-in modules must be imported with a namespace and cannot be imported without one.

B Built-in modules can be imported multiple times without any namespace conflicts.

C Built-in modules are automatically available without any import statement.

D Built-in modules can only be imported using @import, not @use.

💡 Hint

Think about how @use handles namespaces for modules.

When you import built-in modules with @use, you must use their namespace to access their functions or variables. This prevents naming conflicts.

❓ selector

advanced

Which option correctly uses a built-in Sass module function with @use?

Given the Sass code below, which option correctly uses the math.div function from the built-in sass:math module to divide 10 by 2?

SASS

@use "sass:math";

.result {
  width: ???;
}

A width: math(10 / 2);

B width: math.div(10, 2);

C width: div(10, 2);

D width: math.division(10, 2);

💡 Hint

Remember to use the namespace and exact function name.

The correct syntax is to call the div function with the math namespace: math.div(10, 2).

❓ layout

advanced

What CSS does this Sass code produce when using @use with sass:list?

Analyze the following Sass code:

@use "sass:list";

.container {
  grid-template-columns: list.join(("1fr", "2fr", "1fr"), " ");
}

What is the resulting CSS for .container?

SASS

@use "sass:list";

.container {
  grid-template-columns: list.join(("1fr", "2fr", "1fr"), " ");
}

A grid-template-columns: 1fr 2fr 1fr;

B grid-template-columns: ("1fr", "2fr", "1fr");

C grid-template-columns: 1fr, 2fr, 1fr;

D grid-template-columns: list.join(1fr 2fr 1fr);

💡 Hint

The list.join function combines list items into a string separated by the given separator.

list.join merges the list items into a single string separated by spaces, producing valid CSS grid columns.

❓ accessibility

expert

What error occurs if you try to use a built-in Sass module function without @use?

Consider this Sass code:

.box {
  width: math.div(20, 4);
}

What happens if you do NOT include @use "sass:math"; at the top?

A Error: Missing semicolon after math.div.

B The code compiles and outputs width: 5;

C Warning: math.div is deprecated but still works.

D Error: Undefined function "math.div".

💡 Hint

Think about how Sass knows where functions come from.

Without importing the sass:math module using @use, the math namespace and its functions are unknown, causing an undefined function error.

Practice

1. What does the Sass @use rule do when importing built-in modules?

easy

A. It imports CSS files directly into Sass without any namespace.

B. It imports a built-in Sass module to use its features with a namespace.

C. It compiles Sass files into CSS automatically.

D. It removes unused CSS rules from the stylesheet.

Solution

1. Step 1: Understand the purpose of @use

   The @use rule imports Sass modules and gives access to their functions and variables under a namespace.

2. Step 2: Differentiate from other Sass features

   Unlike @import, @use does not import raw CSS but Sass modules with scoped namespaces.

3. Final Answer:

   It imports a built-in Sass module to use its features with a namespace. -> Option B

4. Quick Check:

   @use imports modules with namespace [OK]

Hint: Remember: @use always adds a namespace to imported modules [OK]

Common Mistakes:

• Confusing @use with @import for CSS files
• Thinking @use compiles Sass to CSS
• Assuming @use removes unused CSS

2. Which of the following is the correct syntax to import the built-in Sass math module using @use?

easy

A. @use "math";

B. @import "sass:math";

C. @use "sass:math";

D. @use math;

Solution

1. Step 1: Recall the correct syntax for built-in modules

   Built-in Sass modules are imported with @use "sass:module-name"; syntax.

2. Step 2: Check each option

   @use "sass:math"; uses the correct syntax with quotes and the prefix sass:. Others miss quotes, prefix, or use @import.

3. Final Answer:

   @use "sass:math"; -> Option C

4. Quick Check:

   Built-in modules need @use "sass:module"; [OK]

Hint: Built-in modules always use "sass:" prefix inside quotes [OK]

Common Mistakes:

• Omitting quotes around module name
• Using @import instead of @use
• Forgetting the "sass:" prefix

3. Given the Sass code:

@use "sass:color";

.my-text {
  color: color.scale(color.$blue, $lightness: 20%);
}

What color effect does this code apply to .my-text?

medium

A. It causes a syntax error.

B. It makes the blue color 20% darker.

C. It changes the blue color to red.

D. It makes the blue color 20% lighter.

Solution

1. Step 1: Understand color.scale function

   The color.scale function adjusts color properties like lightness by the given percentage.

2. Step 2: Analyze the argument $lightness: 20%

   This increases the lightness of the blue color by 20%, making it lighter.

3. Final Answer:

   It makes the blue color 20% lighter. -> Option D

4. Quick Check:

   color.scale with positive lightness increases brightness [OK]

Hint: Positive $lightness in color.scale makes color lighter [OK]

Common Mistakes:

• Confusing lightness increase with darkening
• Assuming color changes hue instead
• Thinking the code has syntax errors

4. What is wrong with this Sass code snippet?

@use "sass:math";

.box {
  width: math.percentage(0.5);
}

medium

A. The math.percentage() function does not exist; it should be math.percent().

B. The @use statement is missing a semicolon.

C. The function name should be math.percent() instead of math.percentage().

D. There is no error; the code is correct.

Solution

1. Step 1: Check the function name in the math module

   The correct function to convert a decimal to a percentage is math.percent(), not math.percentage().

2. Step 2: Verify the rest of the code

   The @use statement is correct and has a semicolon; only the function name is wrong.

3. Final Answer:

   The math.percentage() function does not exist; it should be math.percent(). -> Option A

4. Quick Check:

   Use math.percent() for percentage conversion [OK]

Hint: Remember: math.percent(), not math.percentage() [OK]

Common Mistakes:

• Using incorrect function name math.percentage()
• Thinking @use needs no semicolon
• Assuming code is error-free

5. You want to use the Sass math module to calculate the width as 75% of 1200px. Which code correctly imports the module and calculates the width?

hard

A. @use "sass:math";
.container {
width: math.div(75, 100) * 1200px;
}

B. @use "sass:math";
.container {
width: math.percent(0.75);
}

C. @use "sass:math";
.container {
width: math.div(75%, 100) * 1200px;
}

D. @use "sass:math";
.container {
width: math.percent(75) * 1200px;
}

Solution

1. Step 1: Import the math module correctly

   The code uses @use "sass:math"; which is correct for built-in modules.

2. Step 2: Calculate 75% of 1200px correctly

   Using math.div(75, 100) divides 75 by 100 to get 0.75, then multiplies by 1200px for the width.

3. Step 3: Check other options for errors

   @use "sass:math"; .container { width: math.percent(0.75); } sets width to 75% of the parent, not a fixed 900px. @use "sass:math"; .container { width: math.div(75%, 100) * 1200px; } uses math.div(75%, 100) which equals 0.75% (dividing percentage by unitless keeps %), so 0.75% * 1200px = 9px. @use "sass:math"; .container { width: math.percent(75) * 1200px; } uses math.percent(75) which returns 7500%.

4. Final Answer:

   @use "sass:math"; .container { width: math.div(75, 100) * 1200px; } -> Option A

5. Quick Check:

   Use math.div for division, multiply for percentage calculation [OK]

Hint: Use math.div(percentage, 100) to get decimal for calculations [OK]

Common Mistakes:

• Using math.percent() for relative percentage instead of fixed pixel calculation
• Dividing percentages by unitless numbers (keeping % unit)
• Misunderstanding multiplication with units