SASS | Introspection Functions

SASS Introspection functions allow you to inspect the conditions of SASS itself. You can not use them when you are making stylesheets, but they’re crucial for knowing what is going on when something does not work according to the way that you want. 

The following table contains all introspection functions in SASS: 

Function	Description	Example
variable-exists($name)	This method returns a Boolean value that represent whether the given variable exists, either globally or locally.	$x: 40px;  variable-exists($x)  Output: true  variable-exists($y)  Output: false
global-variable-exists($name)	This method returns a Boolean value that represent whether the given variable exists globally.	$x: 40px;  global-variable-exists($x);  Output: true
mixin-exists($name)	This method returns a Boolean value that represent whether the given mixin exists.	@mixin text-color {color: blue; }  Output: true
inspect($value)	This methods returns the value as it is given by SASS.	inspect(54)  Output: “54”
type-of($value)	This methods returns a string that represent the SASS data type of the value.	type-of(5 6 4 7 8 9)  Output: “list”
unit(number)	This methods returns the unit associated with the number, or a null string if the number is unitless.	$x: 40px;  unit($x);  Output: “px”  $x: 40;  unit($x);  Output: “”
unitless($number)	This methods returns a Boolean value that represent whether the given number has a unit associated with it or not.	$x: 40px;  unitless($x);  Output: false
comparable($number1, $number2)	This methods returns a Boolean value that represent whether the given numbers can be added, subtracted or compared.	comparable(2em, 7em)  Output: true  comparable(2em, 4px)  Output: false  comparable(2em, 7)  Output: true