---
title: Map Functions
---

<% function 'keywords($args)', returns: 'map' do %>
  Returns the keywords passed to a mixin or function that takes [arbitrary
  arguments][]. The `$args` argument must be an [argument list][].

  [arbitrary arguments]: ../at-rules/mixin#taking-arbitrary-arguments
  [argument list]: ../values/lists#argument-lists

  The keywords are returned as a map from argument names as unquoted strings (not
  including `$`) to the values of those arguments.

  <%= partial 'code-snippets/example-mixin-arbitrary-keyword-arguments' %>
<% end %>


<% function 'map-get($map, $key)' do %>
  Returns the value in `$map` associated with `$key`.

  If `$map` doesn't have a value associated with `$key`, returns [`null`][].

  [`null`]: ../values/null

  <%= partial 'code-snippets/example-map-get' %>
<% end %>


<% function 'map-has-key($map, $key)', returns: 'boolean' do %>
  Returns whether `$map` contains a value associated with `$key`.

  <% example(autogen_css: false) do %>
    $font-weights: ("regular": 400, "medium": 500, "bold": 700);

    @debug map-has-key($font-weights, "regular"); // true
    @debug map-has-key($font-weights, "bolder"); // false
    ===
    $font-weights: ("regular": 400, "medium": 500, "bold": 700)

    @debug map-has-key($font-weights, "regular")  // true
    @debug map-has-key($font-weights, "bolder")  // false
  <% end %>
<% end %>


<% function 'map-keys($map)', returns: 'list' do %>
  Returns a comma-separated list of all the keys in `$map`.

  <% example(autogen_css: false) do %>
    $font-weights: ("regular": 400, "medium": 500, "bold": 700);

    @debug map-keys($font-weights); // "regular", "medium", "bold"
    ===
    $font-weights: ("regular": 400, "medium": 500, "bold": 700)

    @debug map-keys($font-weights)  // "regular", "medium", "bold"
  <% end %>
<% end %>


<% function 'map-merge($map1, $map2)', returns: 'map' do %>
  Returns a new map with all the keys and values from both `$map1` and `$map2`.

  This can also be used to add a new value or overrwrite a value in `$map1`, by
  passing a single key/value pair as `$map2`.

  If both `$map1` and `$map2` have the same key, `$map2`'s value takes precedence.

  All keys in the returned map that also appear in `$map1` have the same order as
  in `$map1`. New keys from `$map2` appear at the end of the map.

  <% example(autogen_css: false) do %>
    $light-weights: ("lightest": 100, "light": 300);
    $heavy-weights: ("medium": 500, "bold": 700);

    @debug map-merge($light-weights, $heavy-weights);
    // (
    //   "lightest": 100,
    //   "light": 300,
    //   "medium": 500,
    //   "bold": 700
    // )

    // map-merge() can be used to add a single key/value pair to a map.
    @debug map-merge($light-weights, ("lighter": 200));
    // ("lightest": 100, "light": 300, "lighter": 200)

    // It can also be used to overwrite a value in a map.
    @debug map-merge($light-weights, ("light": 200));
    // ("lightest": 100, "light": 200)
    ===
    $light-weights: ("lightest": 100, "light": 300)
    $heavy-weights: ("medium": 500, "bold": 700)

    @debug map-merge($light-weights, $heavy-weights)
    // (
    //   "lightest": 100,
    //   "light": 300,
    //   "medium": 500,
    //   "bold": 700
    // )

    // map-merge() can be used to add a single key/value pair to a map.
    @debug map-merge($light-weights, ("lighter": 200))
    // ("lightest": 100, "light": 300, "lighter": 200)

    // It can also be used to overwrite a value in a map.
    @debug map-merge($light-weights, ("light": 200))
    // ("lightest": 100, "light": 200)
  <% end %>
<% end %>


<% function 'map-remove($map, $keys...)', returns: 'map' do %>
  Returns a copy of `$map` without any values associated with `$keys`.

  If a key in `$keys` doesn't have an associated value in `$map`, it's ignored.

  <% example(autogen_css: false) do %>
    $font-weights: ("regular": 400, "medium": 500, "bold": 700);

    @debug map-remove($font-weights, "regular"); // ("medium": 500, "bold": 700)
    @debug map-remove($font-weights, "regular", "bold"); // ("medium": 500)
    @debug map-remove($font-weights, "bolder");
    // ("regular": 400, "medium": 500, "bold": 700)
    ===
    $font-weights: ("regular": 400, "medium": 500, "bold": 700)

    @debug map-remove($font-weights, "regular")  // ("medium": 500, "bold": 700)
    @debug map-remove($font-weights, "regular", "bold")  // ("medium": 500)
    @debug map-remove($font-weights, "bolder")
    // ("regular": 400, "medium": 500, "bold": 700)
  <% end %>
<% end %>


<% function 'map-values($map)', returns: 'list' do %>
  Returns a comma-separated list of all the values in `$map`.

  <% example(autogen_css: false) do %>
    $font-weights: ("regular": 400, "medium": 500, "bold": 700);

    @debug map-values($font-weights); // 400, 500, 700
    ===
    $font-weights: ("regular": 400, "medium": 500, "bold": 700)

    @debug map-values($font-weights)  // 400, 500, 700
  <% end %>
<% end %>