SASS, or Syntactically Awesome Style Sheets, is a very popular preprocessor scripting language among developers, used to enhance the functionality of CSS. SASS allows developers to use variables, nesting, mixins, and other advanced features not available in CSS.
One of the key features of using SASS is the ability to declare variables, which are nothing more than placeholders for values that we can reuse throughout our web application stylesheets. Variables help save developers time and effort by allowing them to update multiple values at once by making the code more readable and easier to maintain.
Sometimes, we may want to set a variable to empty, which in other languages means setting the variable to null or undefined. This is useful when we want to create a placeholder variable and can assign a value to it later in the application. In this article, we will learn how to set a variable not equal to anything in SASS.
prerequisites
To run SASS in HTML, make sure you have the SASS compiler installed in your IDE (just like in VS Code), download and install the SASS compiler using the following command -
npm install -g sass
This will install the SASS compiler globally on your system. Next, create a new file with a .scss extension that will contain our SASS code.
After that, import the SASS file into the HTML file. In the HTML file, add a link to your SASS file using the 'link' tag in the head section. The link's rel attribute should be set to "stylesheet" and its href attribute should be set to the path to your SASS file.
Different ways to set a variable to not be equal to anything in SASS
To set a variable not equal to any value, there are several ways, such as using the null keyword, the unset function, or the #{} interpolation method. Let us discuss all these methods in detail one by one.
Method 1: Use Null keyword
In SASS, the null keyword is used to indicate the absence of a value. When a variable is set to null, it means that the variable has not been assigned any value. This is useful when you want to declare a variable but don't want to assign a value to it immediately.
grammar
To set a variable to not be equal to anything in SASS, just use the null keyword as shown below -
$newVar: null;
Alternatively, we can set a variable to null by assigning it to a variable that has already been set to null
$newOtherVar: $newVar;
Example
Let’s see a complete example of how to set a variable to nothing using null keyword.
HTML code
<!DOCTYPE html>
<html>
<head>
<title>Example to set the variable to equal nothing using null keyword</title>
<style>
/* Add the CSS compiled code below */
</style>
</head>
<body>
<h1 id="Welcome-to-Tutorialspoint">Welcome to Tutorialspoint!</h1>
<p>The one stop solution to learn technology articles.</p>
</body>
</html>
SASS code
Below is the SASS code where we declare the variable $newVar with a value equal to null.
$newVar: null;
body {
background-color: $newVar;
color: $newVar;
font-size: $newVar;
}
Compiled CSS code
The following is the compiled code generated after compiling the above SASS code with the help of the SASS compiler. To see the changes in the document, make sure to add the following code between the
body {
background-color: ;
color: ;
font-size: ;
}
Method 2: Use the Unset function
Another way to set a variable to empty in SASS is to use the unset function. The unset function removes a variable from memory, effectively setting it to null. Here is an example of how to set a variable to null using the unset function.
grammar
$newVar: 15; $newVar: unset($newVar);
In the above syntax, $newVar is first assigned a value of 15. Then use the unset function to remove $newVar from memory, effectively setting it to null.
Example
Let’s see a complete example of how to set a variable to None using the unset function.
HTML code
<!DOCTYPE html>
<html>
<head>
<title>Example to set the variable to equal nothing using unset function</title>
<style>
/* Add the CSS compiled code below */
</style>
</head>
<body>
<h1 id="Welcome-to-Tutorialspoint">Welcome to Tutorialspoint!</h1>
<p>The one stop solution to learn technology articles.</p>
</body>
</html>
SASS code
The following is the SASS code, in which we declare two variables $newVar1 and $newVar2, whose values are equal to 15 and 12 respectively. Now, the unset function is used to remove $newVar1 and $newVar2 from memory, effectively setting them to null.
$newVar1: 15;
$newVar1: 12;
$newVar1: unset($newVar1);
$newVar2: unset($newVar2);
h1 {
font-size: $newVar1;
}
p {
font-size: $newVar2;
}
Compiled CSS code
The following is the compiled code generated after compiling the above SASS code with the help of the SASS compiler. To see the changes in the document, make sure to add the following code between the
h1 {
font-size: ;
}
p {
font-size: ;
}
Method 3: Use #{} interpolation
The #{} interpolation syntax is evaluated at compile time, so in compiled CSS, the resulting value of $newVar will be the empty string. This may not be desired behavior in some situations, so use this technique with caution when appropriate.
grammar
$newVar: #{" "};
In the above syntax, $newVar is set to an empty string, which is created using #{} interpolation syntax with a space inside. This technique is useful when you need to set a variable to an empty string instead of null.
Example
Let's look at an example of setting a variable to None using the interpolation method.
HTML code
<!DOCTYPE html>
<html>
<head>
<title>Example to set the variable to equal nothing using Interpolation</title>
<style>
/* Add the CSS compiled code below */
</style>
</head>
<body>
<h1 id="Welcome-to-Tutorialspoint">Welcome to Tutorialspoint!</h1>
</body>
</html>
SASS code
Below is the SASS code where we declare a variable $newVar and set it to the empty string using interpolation syntax.
$newVar: #{" "};
body {
padding: $newVar;
margin: $newVar;
}
编译的 CSS 代码
下面是在 SASS 编译器的帮助下编译上述 SASS 代码后生成的编译代码。要查看文档中的更改，请确保在相应 HTML 文件中的
body {
padding: ;
margin: ;
}
结论
在本文中，我们了解了如何使用不同的方法在 SASS 中将变量设置为空，包括使用 null 关键字、unset 函数和 #{} 插值语法。详细介绍这些技术，它们在不同情况或项目需求中非常有用，在这些情况或项目需求中，我们需要创建一个占位符变量，稍后可以在应用程序中为其分配值。
在SASS中，声明变量更具可读性和可维护性，从而节省了开发人员的时间和精力。要使用 SASS，请确保在 IDE 中安装了 SASS 编译器，就像上面讨论的在 VS Code 中使用 SASS 的过程一样，我们需要将 SASS 文件正确导入到 HTML 文件中。
The above is the detailed content of How to set a variable not equal to any value in SASS?. For more information, please follow other related articles on the PHP Chinese website!
Demystifying Screen Readers: Accessible Forms & Best PracticesMar 08, 2025 am 09:45 AMThis is the 3rd post in a small series we did on form accessibility. If you missed the second post, check out "Managing User Focus with :focus-visible". In
Create a JavaScript Contact Form With the Smart Forms FrameworkMar 07, 2025 am 11:33 AMThis tutorial demonstrates creating professional-looking JavaScript forms using the Smart Forms framework (note: no longer available). While the framework itself is unavailable, the principles and techniques remain relevant for other form builders.
Adding Box Shadows to WordPress Blocks and ElementsMar 09, 2025 pm 12:53 PMThe CSS box-shadow and outline properties gained theme.json support in WordPress 6.1. Let's look at a few examples of how it works in real themes, and what options we have to apply these styles to WordPress blocks and elements.
Working With GraphQL CachingMar 19, 2025 am 09:36 AMIf you’ve recently started working with GraphQL, or reviewed its pros and cons, you’ve no doubt heard things like “GraphQL doesn’t support caching” or
Making Your First Custom Svelte TransitionMar 15, 2025 am 11:08 AMThe Svelte transition API provides a way to animate components when they enter or leave the document, including custom Svelte transitions.
Classy and Cool Custom CSS Scrollbars: A ShowcaseMar 10, 2025 am 11:37 AMIn this article we will be diving into the world of scrollbars. I know, it doesn’t sound too glamorous, but trust me, a well-designed page goes hand-in-hand
Show, Don't TellMar 16, 2025 am 11:49 AMHow much time do you spend designing the content presentation for your websites? When you write a new blog post or create a new page, are you thinking about
What the Heck Are npm Commands?Mar 15, 2025 am 11:36 AMnpm commands run various tasks for you, either as a one-off or a continuously running process for things like starting a server or compiling code.
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment
WebStorm Mac version
Useful JavaScript development tools
Notepad++7.3.1
Easy-to-use and free code editor
mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.
