sass-site/source/documentation/values/booleans.md

title	introduction
Booleans	Booleans are the logical values `true` and `false`. In addition their literal forms, booleans are returned by [equality](/documentation/operators/equality) and [relational](/documentation/operators/relational) operators, as well as many built-in functions like [`math.comparable()`](/documentation/modules/math#comparable) and [`map.has-key()`](/documentation/modules/map#has-key).

{% codeExample 'booleans', false %} @use "sass:math";

@debug 1px == 2px; // false @debug 1px == 1px; // true @debug 10px < 3px; // false @debug math.comparable(100px, 3in); // true

@use "sass:math"

@debug 1px == 2px // false @debug 1px == 1px // true @debug 10px < 3px // false @debug math.comparable(100px, 3in) // true {% endcodeExample %}

You can work with booleans using boolean operators. The and operator returns true if both sides are true, and the or operator returns true if either side is true. The not operator returns the opposite of a single boolean value.

{% codeExample 'boolean-operators', false %} @debug true and true; // true @debug true and false; // false

@debug true or false; // true @debug false or false; // false

@debug not true; // false @debug not false; // true

@debug true and true // true @debug true and false // false

@debug true or false // true @debug false or false // false

@debug not true // false @debug not false // true {% endcodeExample %}

Using Booleans

You can use booleans to choose whether or not to do various things in Sass. The @if rule evaluates a block of styles if its argument is true:

{% render 'code_snippets/example-if' %}

The if() function returns one value if its argument is true and another if its argument is false:

{% codeExample 'if-function', false %} @debug if(true, 10px, 30px); // 10px @debug if(false, 10px, 30px); // 30px

@debug if(true, 10px, 30px) // 10px @debug if(false, 10px, 30px) // 30px {% endcodeExample %}

{% render 'doc_snippets/truthiness-and-falsiness' %}