Skip to main
Article

Map-Set vs. Map-Merge

The difference between map-set and map-merge? Almost nothing.

When I first heard that Sass 3.3 had no map-set function, I was confused. Why force me to create a map, and then merge it? That sounds like two steps to accomplish one simple task! But that’s not the case. Map-merge is a much more powerful function, and using it to set a key in an existing map is quite straight-forward. In fact, I couldn’t come up with a map-set function that shaved off more than a few keystrokes. Here’s the comparison:

// a map!
$map: (
  1: hello,
  2: world,
);

// a map-set function (not included with Sass)
@function map-set($map, $key, $value) {
  $new: (
    $key: $value,
  );
  @return map-merge($map, $new);
}

// the difference between map-set and map-merge: almost nothing.
$merge: map-merge(
  $map,
  (
    2: New York,
  )
);
$set: map-set($map, 2, New York);

Recent Articles

  1. A chain-link gate in black and white with a sign that says closed indefinitely, and a smaller warning with gruesome icons for entrapment (a person being smashed) and pinching (a hand going through gears)
    Article post type

    How do we move logical shorthands forward?

    There are several proposals, but one major road block

    We’re trying to make progress on shorthand syntax for CSS logical properties. But the path forward depends on where we hope to be a decade from now.

    see all Article posts
  2. block-size, inline-size, size?
    Article post type

    Support Logical Shorthands in CSS

    Can we get this process unstuck?

    The CSS Working Group recently resolved to add a size shorthand for setting both the width and height of an element. Many people asked about using it to set the ‘logical’ inline-size and block-size properties instead. But ‘logical shorthands’ have been stalled in the working group for years. Can we…

    see all Article posts
  3. OddContrast displays sRGB gamut range in P3 color format and an estimate of foreground alpha value ratio.
    Article post type

    New Features for OddContrast

    OddContrast gets new features – including the ability to swap background and foreground colors, and display color gamut ranges on the color sliders. Contrast ratios now incorporate foreground color alpha values.

    see all Article posts