mirror of
https://github.com/danog/sass-site.git
synced 2024-12-05 13:28:56 +01:00
94 lines
3.3 KiB
Plaintext
94 lines
3.3 KiB
Plaintext
---
|
|
title: Numbers
|
|
introduction: >
|
|
Numbers in Sass have two components: the number itself, and its units. For
|
|
example, in `16px` the number is `16` and the unit is `px`. Numbers can have
|
|
no units, and they can have complex units. See [Units](#units) below for more
|
|
details.
|
|
---
|
|
|
|
{% codeExample 'numbers', false %}
|
|
@debug 100; // 100
|
|
@debug 0.8; // 0.8
|
|
@debug 16px; // 16px
|
|
@debug 5px * 2px; // 10px*px (read "square pixels")
|
|
===
|
|
@debug 100 // 100
|
|
@debug 0.8 // 0.8
|
|
@debug 16px // 16px
|
|
@debug 5px * 2px // 10px*px (read "square pixels")
|
|
{% endcodeExample %}
|
|
|
|
{% markdown %}
|
|
Sass numbers support the same formats as CSS numbers, including [scientific
|
|
notation][], which is written with an `e` between the number and its power
|
|
of 10. Because support for scientific notation in browsers has historically
|
|
been spotty, Sass always compiles it to fully expanded numbers.
|
|
|
|
[scientific notation]: https://en.wikipedia.org/wiki/Scientific_notation
|
|
{% endmarkdown %}
|
|
|
|
{% codeExample 'scientific-notation', false %}
|
|
@debug 5.2e3; // 5200
|
|
@debug 6e-2; // 0.06
|
|
===
|
|
@debug 5.2e3 // 5200
|
|
@debug 6e-2 // 0.06
|
|
{% endcodeExample %}
|
|
|
|
{% headsUp %}
|
|
Sass doesn't distinguish between whole numbers and decimals, so for example
|
|
`math.div(5, 2)` returns `2.5` rather than `2`. This is the same behavior as
|
|
JavaScript, but different than many other programming languages.
|
|
{% endheadsUp %}
|
|
|
|
{% render 'doc_snippets/number-units' %}
|
|
|
|
{% markdown %}
|
|
## Precision
|
|
|
|
{% compatibility 'dart: true', 'libsass: false', 'ruby: "3.5.0"', 'feature: "10 Digit Default"' %}
|
|
LibSass and older versions of Ruby Sass default to 5 digits of numeric
|
|
precision, but can be configured to use a different number. It's recommended
|
|
that users configure them for 10 digits for greater accuracy and
|
|
forwards-compatibility.
|
|
{% endcompatibility %}
|
|
|
|
Sass numbers are represented internally as 64-bit floating point values. They
|
|
support up to 10 digits of precision after the decimal point when serialized
|
|
to CSS and for the purposes of equality. This means a few different things:
|
|
|
|
* Only the first ten digits of a number after the decimal point will be
|
|
included in the generated CSS.
|
|
|
|
* Operations like [`==`][] and [`>=`][] will consider two numbers equivalent
|
|
if they're the same up to the tenth digit after the decimal point.
|
|
|
|
* If a number is less than `0.0000000001` away from an integer, it's
|
|
considered to be an integer for the purposes of functions like
|
|
[`list.nth()`][] that require integer arguments.
|
|
|
|
[`==`]: /documentation/operators/equality
|
|
[`>=`]: /documentation/operators/relational
|
|
[`list.nth()`]: /documentation/modules/list#nth
|
|
{% endmarkdown %}
|
|
|
|
{% codeExample 'precision', false %}
|
|
@debug 0.012345678912345; // 0.0123456789
|
|
@debug 0.01234567891 == 0.01234567899; // true
|
|
@debug 1.00000000009; // 1
|
|
@debug 0.99999999991; // 1
|
|
===
|
|
@debug 0.012345678912345 // 0.0123456789
|
|
@debug 0.01234567891 == 0.01234567899 // true
|
|
@debug 1.00000000009 // 1
|
|
@debug 0.99999999991 // 1
|
|
{% endcodeExample %}
|
|
|
|
{% funFact %}
|
|
Numbers are rounded to 10 digits of precision *lazily* when they're used in a
|
|
place where precision is relevant. This means that math functions will work
|
|
with the full number value internally to avoid accumulating extra rounding
|
|
errors.
|
|
{% endfunFact %}
|