sass-notes

# DATA TYPE
    string (e.g. "Hello world" , kittens )
    number (e.g. 42 , 1337px )
    color (e.g. hotpink , rgb(1, 33, 7) , #BADA55 )
    list (e.g. (a, b, c) , a b c )
    map (e.g. (a: 1, b: 2) )
    bool ( true or false )
    null ( null )
    
# list (like an array)
    $value: ('Hello', 'world');
    The first point to know about lists is that it’s the delimiter (either spaces or commas) that makes a list, not the
    wrapping parentheses

# map
    $message-themes: (
    'info': deepskyblue,
    'danger': tomato,
    );
    .message-confirm {color: map-get($message-themes,'info');}

    map is a series of pairs of associated keys and values where keys are unique to each map. While a list is usually tied  
    to a specific order—as it is basically the only way to find a value within it—a map uses its keys to find their associated 
    value.
    
    You have to know that in Sass—unlike JavaScript, for instance—keys of a map can be of any type and not just strings.

# NOT !
    Unlike most other languages, Sass lacks a bang operator ( ! ) to get the opposite of a value, such as if (!value) .
    Instead, it provides the not keyword
    
# NULL
    null is both the value and its type, making it a very specific element of the Sass language
    
# VARIABLE
    This is referred to as variable shadowing in Sass. When declaring in an inner scope
    (such as a function or rule set) a variable whose name already exists in the global
    namespace, the local variable is said to be shadowing the global one    
    
    ~ global!
            To definitely override a global variable from a local scope, we use the !global flag.
    ~ default!
            Bear in mind that variables with null value are treated as unassigned by default,
            which means that a variable assignment with !default will override a variable as-
            signment to null :
            
# Interpolation
    width: calc(100% - $sidebar-width); // calc(100% - $sidebar-width)
    width: calc(100% - #{$sidebar-width}); // calc(100% - 300px)
    
    We are almost done with variables. The last point to grasp is the concept of inter-
    polation. Often referred to as variable interpolation or variable substitution, this
    concept is not unique to Sass
    
# CONSTANT
    Sass does not support actual constants.
    
    
# FUNCTION
    Keep in mind that functions cannot be defined within mixins or other functions.
    
    Parameters can also have a default value—in which case they are called optional parameters. Note that optional 
    parameters must come after any non-optional parameter.
    
    // `$a` is mandatory and `$b` is optional (default value being 2)
    @function multiply($a, $b: 2) {
    @return ($a * $b);
    }