sass-site/source/documentation/values/null.html.md.erb

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---
title: null
---
The value `null` is the only value of its type. It represents the absence of a
value, and is often returned by [functions][] to indicate the lack of a result.
[functions]: ../at-rules/function
<% example(autogen_css: false) do %>
@debug str-index("Helvetica Neue", "Roboto"); // null
@debug map-get(("large": 20px), "small"); // null
@debug &; // null
===
@debug str-index("Helvetica Neue", "Roboto") // null
@debug map-get(("large": 20px), "small") // null
@debug & // null
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<% end %>
If a [list][] contains a `null`, that `null` is omitted from the generated CSS.
[list]: lists
<% example do %>
$fonts: ("serif": "Helvetica Neue", "monospace": "Consolas");
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h3 {
font: 18px bold map-get($fonts, "sans");
}
===
$fonts: ("serif": "Helvetica Neue", "monospace": "Consolas")
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h3
font: 18px bold map-get($fonts, "sans")
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<% end %>
If a property value is `null`, that property is omitted entirely.
<% example do %>
$fonts: ("serif": "Helvetica Neue", "monospace": "Consolas");
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h3 {
font: {
size: 18px;
weight: bold;
family: map-get($fonts, "sans");
}
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}
===
$fonts: ("serif": "Helvetica Neue", "monospace": "Consolas")
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h3
font:
size: 18px
weight: bold
family: map-get($fonts, "sans")
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<% end %>
`null` is also [*falsey*][], which means it counts as `false` for any rules or
[operators][] that take booleans. This makes it easy to use values that can be
`null` as conditions for [`@if`][] and [`if()`][].
[*falsey*]: ../at-rules/control/if#truthiness-and-falsiness
[operators]: ../operators/boolean
[`@if`]: ../at-rules/control/if
[`if()`]: ../functions#if
<%= partial 'code-snippets/example-if-parent-selector' %>