What are Sass functions?

SASS (Syntactically Awesome Style Sheets) functions are similar to mixins in that they allow you to group CSS declarations together and reuse them throughout your stylesheet. However, unlike mixins, which are used to include a set of styles, functions in SASS are used to perform operations and return a value that can be used in a CSS property value.

Functions in SASS are defined using the @function keyword, followed by the name of the function, and a set of instructions inside curly braces. For example, the following is a function that calculates the width of an element based on its padding:

@function calculateWidth($padding) {
    @return 100% - ($padding * 2);
}

To use a function, you call it by its name, passing any required arguments. The value returned by the function can be used in a CSS property value. For example, to set the width of an element with class .container using the calculateWidth function, you would write:

.container {
    width: calculateWidth(20px);
    padding: 20px;
}

SASS functions can be useful for performing complex calculations, creating dynamic styles, and making your CSS more reusable. They can be used to perform mathematical operations, manipulate colors and strings, and even generate CSS code.

For example, you can use SASS function to generate a color function to lighten or darken a color by a certain percentage, or you can use a function to calculate the font-size based on the screen size.

Functions can help to make your CSS more modular, maintainable and dynamic, by encapsulating complex logic in reusable functions, it will make your code more readable and easy to update.