A Complete Guide To CSS Variables [With Examples]

Variables in CSS are used to store values that can be reused throughout the stylesheet. They help reduce redundancy and make the code more maintainable. In this guide, we will learn how to use variables in CSS from its implementation to responsiveness test. SUMMARY: 1. Introduction To Variables In CSS 2. Implementing Variables In CSS 3. Scopes Of Variables In CSS 4. Precedence And Inheritance In Variables In CSS 5. Fallback Values In CSS Variables 6. Exceptions In CSS Variables 7. Browser Compatibility Of CSS Variables 8. Responsiveness Test Of Variables In CSS SUMMARY: 1. Introduction To Variables In CSS Variables in CSS are used to store values that can be reused throughout the stylesheet. They help reduce redundancy and make the code more maintainable. In this guide, we will learn how to use variables in CSS from its implementation to responsiveness test. 2. Implementing Variables In CSS To implement a variable in CSS, first, give the variable a name, then add two hyphens (--) as a prefix. The syntax for declaring a variable in CSS is var(--name, value). For example: :root { --my_variable: <value>; } In this code, we have declared a variable named "my_variable" with the value "<value>" under the root pseudo class. The scope of this variable will be throughout the document from its declaration point. 3. Scopes Of Variables In CSS The scope property is akin to a variable’s scope in the programming languages. The CSS variable’s scope is no different. This is how you can define a CSS variable under two scopes: Global Scope – One declaration For All The scope property is akin to a variable’s scope in the programming languages. The CSS variable’s scope is no different. This is how you can define a CSS variable under two scopes: Local Scope – Bounded By Selector Walls 4. Precedence And Inheritance In Variables In CSS Now we know that when a variable is defined with a global scope, its existence is defined in the complete document from the time of its declaration. But other programming languages like Python or C++ have an open field between functions where you have the option to define the global scope. 5. Fallback Values In CSS Variables The fallback values are the second argument used in the “var()” function, which denotes the substitution of a CSS variable. Fallback values take their name from the job they do – they are used when you fall back with the original variable values. 6. Exceptions In CSS Variables Once you know how to use variables in CSS, you will see it is flexible and easy to use. However, they do have a few exceptions that one should remember before declaring and substituting the variables. 7. Browser Compatibility Of CSS Variables CSS variables enjoy great support from every major browser. If you know how to use variables in CSS, you can ensure that exceptions and fallbacks are correctly working as per the code. 8. Responsiveness Test Of Variables In CSS The most buzzed word of the web development world currently is responsiveness. With Google specifying the responsiveness wherever possible and multiple devices flooding the market, responsive web design has become a priority in itself. Variables in CSS are not visual elements that can be tested with window resize functionality for responsiveness. But they do affect the components that are visual such as div, images, or anything else. Therefore, responsiveness test is important with the CSS media queries whether variables in CSS support them or not.