Working with boolean values and expressions in SCSS

SCSS (Sassy CSS) is a powerful extension of CSS that introduces a range of features to enhance the flexibility and maintainability of stylesheets. One of these features is the use of boolean values and expressions, which enable you to add conditional logic to your styles. This article explores how to work with boolean values and expressions in SCSS, providing practical examples and best practices.

Introduction to Boolean Values in SCSS

Boolean values in SCSS are a type of data that can either be `true` or `false`. These values are commonly used in conditional logic to determine whether certain styles should be applied. Boolean expressions are logical statements that evaluate to either `true` or `false`, and they can be combined with conditional directives to control the application of styles.

Basic Example:

/* Basic Example of Boolean Values */
$is-dark-theme: true;

.container {
  @if $is-dark-theme {
    background-color: #333;
    color: #fff;
  } @else {
    background-color: #fff;
    color: #000;
  }
}

In this example, the `@if` directive checks if the `$is-dark-theme` variable is `true`. If it is, the container has a dark background and light text. Otherwise, it uses a light background and dark text.

Combining Boolean Expressions

Boolean expressions can be combined using logical operators to create more complex conditions. The most commonly used logical operators are `and`, `or`, and `not`.

Example with Logical Operators:

/* Example of Combining Boolean Expressions */
$is-dark-theme: true;
$is-logged-in: false;

.container {
  @if $is-dark-theme and $is-logged-in {
    background-color: #333;
    color: #fff;
  } @else {
    background-color: #fff;
    color: #000;
  }
}

In this example, the `@if` directive checks if both `$is-dark-theme` and `$is-logged-in` are `true`. If both conditions are met, the container has a dark background and light text. Otherwise, it uses a light background and dark text.

Using Functions with Boolean Expressions

Functions in SCSS can return boolean values and be used in conditional expressions. This allows you to encapsulate complex logic within functions and reuse them throughout your stylesheets.

Function Example:

/* Function that Returns a Boolean Value */
@function is-large-screen($screen-width) {
  @if $screen-width > 1200px {
    @return true;
  } @else {
    @return false;
  }
}

.sidebar {
  @if is-large-screen(1300px) {
    width: 300px;
  } @else {
    width: 200px;
  }
}

In this example, the `is-large-screen` function returns a boolean value based on the screen width. This function is used in the `.sidebar` class to set different widths based on the screen size.

Practical Example: Theme Toggling

Theme toggling is a common use case for boolean values in SCSS. By using boolean variables and conditional logic, you can easily switch between different themes in your stylesheets.

HTML Structure:

<div class="theme-toggle">
  <p>Toggle Theme Example</p>
</div>

SCSS Styles:

/* Variables for Theme Toggling */
$is-dark-theme: false;

.theme-toggle {
  @if $is-dark-theme {
    background-color: #333;
    color: #fff;
  } @else {
    background-color: #fff;
    color: #000;
  }
}

In this example, the `@if` directive checks the value of the `$is-dark-theme` variable to toggle between a dark and light theme for the `.theme-toggle` class.

Using Boolean Expressions with Mixins

Mixins in SCSS allow you to group styles together and reuse them across your stylesheets. By incorporating boolean expressions into mixins, you can create more flexible and dynamic styling solutions.

Mixin Example:

/* Mixin with Boolean Expressions */
@mixin responsive-padding($is-mobile) {
  @if $is-mobile {
    padding: 10px;
  } @else {
    padding: 20px;
  }
}

.box {
  @include responsive-padding(true);
}

In this example, the `responsive-padding` mixin uses a boolean expression to set different padding values based on whether the `$is-mobile` variable is `true` or `false`. This mixin is used in the `.box` class to apply the appropriate padding.

Creating Responsive Designs with Boolean Expressions

Boolean expressions can play a crucial role in creating responsive designs that adapt to various screen sizes and orientations. By leveraging boolean values and conditional logic, you can ensure your web pages are visually appealing and functional across all devices.

HTML Structure:

<div class="responsive-layout">
  <div class="header">Header</div>
  <div class="main">Main Content</div>
  <div class="sidebar">Sidebar</div>
</div>

SCSS Styles:

/* Mixin for Responsive Layout */
@mixin responsive-layout($is-mobile) {
  @if $is-mobile {
    .responsive-layout {
      display: block;
    }
    .sidebar {
      display: none;
    }
  } @else {
    .responsive-layout {
      display: flex;
    }
    .sidebar {
      display: block;
    }
  }
}

.responsive-layout {
  @include responsive-layout(true);
}

In this example, the `responsive-layout` mixin uses a boolean expression to set different layout styles based on whether the `$is-mobile` variable is `true` or `false`. This mixin is used in the `.responsive-layout` class to create a layout that adapts to different screen sizes.

Fun Facts and Little-Known Insights

• Fun Fact: Boolean values in SCSS are not case-sensitive, meaning you can use `TRUE` or `true` interchangeably.
• Insight: Combining boolean expressions with conditional logic can help you create styles that adapt to different user preferences, such as dark mode and light mode.
• Secret: Boolean expressions can be used to create styles that respond to accessibility settings, such as reduced motion or high contrast.
• Trivia: By using boolean expressions in functions and mixins, you can create highly modular and reusable code that is easy to maintain and extend.
• Hidden Gem: Boolean expressions can help you create more inclusive web designs by adapting styles to different accessibility needs and user preferences.

Best Practices for Using Boolean Values and Expressions

When working with boolean values and expressions in SCSS, it's important to follow best practices to ensure your code remains clean, maintainable, and efficient:

1. Use Descriptive Names

Choose descriptive names for your boolean variables to make their purpose clear. This makes your code more readable and easier to maintain.

2. Keep Conditions Simple

Avoid overly complex boolean expressions. Simple conditions are easier to understand, debug, and maintain.

3. Group Related Conditions

Group related boolean conditions using parentheses to improve readability and clarify the logic.

4. Document Your Logic

Include comments to document the purpose and usage of your boolean expressions. This helps other developers understand how your code works and how to use it effectively.

5. Reuse Functions and Mixins

Encapsulate complex boolean logic within functions and mixins to reuse it across your project. This reduces redundancy and improves maintainability.

Conclusion

Working with boolean values and expressions in SCSS provides a powerful way to add conditional logic to your stylesheets, making them more dynamic and adaptable. By using boolean variables, logical operators, and conditional directives, you can control the application of styles based on specific conditions. Leveraging functions and mixins further enhances the flexibility and reusability of your code. Embrace the power of boolean values and expressions in SCSS to create more sophisticated and maintainable stylesheets.