Use vs Import in Sass: Which One Should You Choose?

When it comes to importing code from other Sass files, you have two options: @use and @import. While both options have their advantages, @use is generally recommended over @import.

By using @use, you can avoid naming conflicts, improve performance, and make your code clearer and more maintainable.

In this article, we’ll explore the differences between @use and @import and provide examples of how to use each one.

@use versus @import

In Sass, there are two ways to include code from another file: @use and @import.

@use is the recommended way to include code from another file in Sass. It allows you to import variables, functions, and mixins from another Sass file and also creates a namespace for them.

The syntax for using @use is as follows:

// Import a Sass file as a module
@use 'file';

// Import specific variables, functions, and mixins
@use 'file' as name;

With @use, you can also specify an alias for the module or file you are importing, which can help avoid naming conflicts.

On the other hand, @import is an older way to include code from another file in Sass. It simply imports the entire Sass file and any variables, functions, or mixins it contains into the current file.

The syntax for using @import is as follows:

// Import a Sass file
@import 'file';

// Import a Sass file and its dependencies
@import 'file1', 'file2', 'file3';

While @import is still supported in Sass, it is being phased out in favor of @use. One reason for this is that @use provides better control over namespace and the ability to specify specific pieces of code to import, which can lead to more efficient code and reduce the risk of naming conflicts.

So, if you are starting a new project or updating an existing one, it’s recommended to use @use instead of @import in your Sass code.

@use over @import

Yes, @use is generally recommended over @import in Sass. Here are some reasons why:

1. Namespacing: @use automatically creates a namespace for the imported module, which can help avoid naming conflicts. This means that variables, mixins, and functions from the imported module are accessed through a namespace, like module.variable or module.mixin, rather than directly. With @import, variables, mixins, and functions are imported into the global namespace, which can lead to naming conflicts.
2. Performance: @use is more performant than @import, especially when used with large codebases. @use allows you to only import what you need from a module, whereas @import imports the entire file and any dependencies. This can result in slower compilation times and larger CSS files. By using @use, you can reduce the amount of code that needs to be compiled and loaded.
3. Clarity: @use makes it clearer which modules are being used in a Sass file, and which variables, mixins, and functions are coming from those modules. This can make it easier for other developers to understand the code and to maintain it over time.

Overall, @use is a more modern and flexible way of importing code from other Sass files, and it is recommended for most use cases. However, @import is still supported in Sass, and there may be situations where it is the better choice, such as when you need to import a single file and all of its dependencies.

Difference between using @use and @import in Sass.

Here is an example that demonstrates the difference between using @use and @import in Sass.

Suppose you have two Sass files: _base.scss and styles.scss. _base.scss contains some variables and a mixin, and styles.scss imports _base.scss to use those variables and the mixin.

Here’s how you would use @import:

// _base.scss
$primary-color: #ff0000;
$secondary-color: #00ff00;

@mixin my-mixin {
  font-size: 16px;
}

// styles.scss
@import 'base';

.my-element {
  background-color: $primary-color;
  color: $secondary-color;
  @include my-mixin;
}

And here’s how you would use @use:

// _base.scss
$primary-color: #ff0000;
$secondary-color: #00ff00;

@mixin my-mixin {
  font-size: 16px;
}

// styles.scss
@use 'base';

.my-element {
  background-color: base.$primary-color;
  color: base.$secondary-color;
  @include base.my-mixin;
}

In the @use example, we use the base. prefix to access the variables and mixin from _base.scss. This makes it clear where these elements are coming from and avoids naming conflicts.

Another advantage of using @use is that we can selectively import only the elements we need from _base.scss, like this:

// styles.scss
@use 'base' with (
  $primary-color: #0000ff
);

.my-element {
  background-color: $primary-color;
  color: base.$secondary-color;
  @include base.my-mixin;
}

In this example, we import _base.scss and override the value of $primary-color with a new value. This allows us to use the mixin and the $secondary-color variable from _base.scss, while customizing the value of $primary-color in the styles.scss file.

Overall, @use provides better clarity, flexibility, and performance over @import, and is generally the recommended way to import code from other Sass files.