Sass Reflective Functions

Sass Reflective Functions

Introspection functions are rarely used when building style sheets.

However, if the code does not work properly, introspection functions are very valuable - they can help understand what went wrong: such as debugging functions.

The following table lists all the introspection functions in Sass:

Functions Description & Example
call(function, arguments...) Call a function with parameters and return the result.
content-exists() Check if the current mixin has been passed an @content block.
feature-exists(feature)

Check if the current Sass implementation supports this feature.

Example:

feature-exists("at-error");

Result: true
function-exists(functionname)

Check if the specified function exists.

Example:

function-exists("nonsense")

Result: false
get-function(functionname, css: false) Return the specified function. If css is true, it will return a regular CSS function.
global-variable-exists(variablename)

Check if the specified global variable exists.

Example:

variable-exists(a)

Result: true
inspect(value) Return the string representation of the value.
mixin-exists(mixinname)

Check if the specified mixin exists.

Example:

mixin-exists("important-text")

Result: true
type-of(value)

Return the type of the value. It can be:

  • number
  • string
  • color
  • list
  • map
  • bool
  • null
  • function
  • arglist

Example:

type-of(15px)

Result: number

type-of(#ff0000)

Result: color
unit(number)

Return the unit associated with the number.

Example:

unit(15px)

Result: px
unitless(number)

Check if the specified number has an associated unit.

Example:

unitless(15px)

Result: false

unitless(15)

Result: true
variable-exists(variablename)

Check if the specified variable exists in the current scope.

Example:

variable-exists(b)

Result: true