Colon - the colon is used for type annotations, in variable declarations and function signatures. The type is the name after the colon. Type annotations are always optional.
Arrow functions - a shorthand syntax for inline functions (lambdas).
Example: x=>x+2
Array comprehensions - an elegant syntax for expressions that operates on lists and arrays.
Example: [x*2 for each (x in [1,2,3])]
Destructuring assignments - a very convenient syntax to "unpack" arrays and objects when assigning.
Example: [a,b] = [1,2]
Multiline regular expressions - allows more readable regular expressions with whitespace and comments.
Triple quoting - an convenient syntax to have strings spanning multiple lines.
Namespaces adds the double-colon operator.
Trailing commas support prevents a common bug with array- and object literals.
Example: [1,2,3,]
Mascara