Variable declaration with $ in SASS

Introduction

Variables let you store values like colors or sizes to reuse them easily in your styles. Using $ helps you keep your code neat and change things quickly.

When you want to use the same color in many places and might change it later.

When you have a font size or spacing value used repeatedly in your design.

When you want to organize your styles by naming important values clearly.

When you want to avoid typing the same value multiple times and reduce mistakes.

Syntax

SASS

$variable-name: value;

Start variable names with $ followed by letters, numbers, underscores, or hyphens.

Assign a value with a colon : and end with a semicolon ;.

Examples

This creates a variable named $primary-color with a blue color value.

SASS

$primary-color: #3498db;

Stores a font size value to use later in your styles.

SASS

$font-size: 1.5rem;

Defines a spacing size variable for consistent gaps or margins.

SASS

$spacing-large: 2rem;

Sample Program

This example shows how to declare variables for a main color and padding. Then it uses them inside a button style. The button changes color a bit when hovered.

SASS

@charset "UTF-8";

$main-color: #e74c3c;
$padding: 1rem;

.button {
  background-color: $main-color;
  padding: $padding;
  color: white;
  border-radius: 0.5rem;
  font-weight: bold;
}

.button:hover {
  background-color: darken($main-color, 10%);
}

Important Notes

You can change the variable value once, and all places using it update automatically.

Variables make your code easier to read and maintain.

Use meaningful names so you remember what each variable is for.

Summary

Variables start with $ and store reusable values.

They help keep your styles consistent and easy to update.

Use variables for colors, sizes, spacing, and more.

Practice

1. What symbol is used to declare a variable in Sass?

easy

A. $

B. #

C. @

D. %

Solution

1. Step 1: Recall Sass variable syntax

   In Sass, variables always start with the $ symbol to distinguish them from other values.

2. Step 2: Identify the correct symbol

   Among the options, only $ is used for variables in Sass.

3. Final Answer:

   $ -> Option A

4. Quick Check:

   Variables start with $ in Sass [OK]

Hint: Remember: Sass variables always begin with $ [OK]

Common Mistakes:

• Using # or @ instead of $ for variables
• Confusing CSS IDs (#) with Sass variables
• Omitting the $ symbol before variable names

2. Which of the following is the correct way to declare a color variable in Sass?

easy

A. main-color: $3498db;

B. $main-color: #3498db;

C. $main-color = #3498db;

D. @main-color: #3498db;

Solution

1. Step 1: Check variable declaration syntax

   Sass variables start with $, followed by the name, a colon, then the value, ending with a semicolon.

2. Step 2: Compare options

   $main-color: #3498db; matches the correct syntax: $main-color: #3498db;. Others use wrong symbols or order.

3. Final Answer:

   $main-color: #3498db; -> Option B

4. Quick Check:

   Variable declaration uses $name: value; [OK]

Hint: Use $name: value; to declare variables in Sass [OK]

Common Mistakes:

• Using = instead of : to assign values
• Placing $ after the variable name
• Using @ instead of $ for variables

3. What will be the background color of the button in this Sass code?

$btn-bg: #ff0000;
button {
  background-color: $btn-bg;
}

medium

A. Blue

B. Green

C. Red

D. No color (default)

Solution

1. Step 1: Identify the variable value

   The variable $btn-bg is assigned the color #ff0000, which is red.

2. Step 2: Check usage in button style

   The button's background-color uses $btn-bg, so it will be red.

3. Final Answer:

   Red -> Option C

4. Quick Check:

   $btn-bg = #ff0000 (red) [OK]

Hint: Match variable value to color code to find output [OK]

Common Mistakes:

• Confusing hex color codes with color names
• Forgetting to use $ before variable name
• Assuming default color if variable is used

4. Identify the error in this Sass variable declaration:

$font-size 16px;

medium

A. Variable name should not start with $

B. Semicolon is missing at the end

C. Value should be in quotes

D. Missing colon between variable name and value

Solution

1. Step 1: Review correct variable syntax

   Sass variables require a colon : between the name and value, like $font-size: 16px;.

2. Step 2: Identify missing colon

   The code misses the colon, causing a syntax error.

3. Final Answer:

   Missing colon between variable name and value -> Option D

4. Quick Check:

   Variable declaration needs colon : [OK]

Hint: Check for colon : after variable name [OK]

Common Mistakes:

• Omitting colon between name and value
• Using = instead of :
• Forgetting semicolon at end (less critical)

5. You want to create a Sass variable for spacing that changes based on screen size. Which is the best way to declare and use it?

$spacing: 1rem;

@media (min-width: 600px) {
  $spacing: 2rem;
}

.container {
  padding: $spacing;
}

hard

A. Variables cannot be redefined inside media queries

B. This works; $spacing changes inside media query

C. Use !default to change variable inside media query

D. Declare two variables and use @if to switch

Solution

1. Step 1: Understand Sass variable scope

   Sass variables are static and cannot change inside media queries because media queries are CSS rules, not Sass logic blocks.

2. Step 2: Evaluate the code behavior

   Redefining $spacing inside @media does not work; Sass processes variables before CSS is generated.

3. Step 3: Correct approach

   To handle responsive spacing, declare separate variables or use mixins/functions with media queries.

4. Final Answer:

   Variables cannot be redefined inside media queries -> Option A

5. Quick Check:

   Sass variables are static, not dynamic in media queries [OK]

Hint: Sass variables are static; media queries can't change them [OK]

Common Mistakes:

• Trying to redefine variables inside media queries
• Assuming Sass variables behave like CSS custom properties
• Not using separate variables or mixins for responsiveness