Literals
A literal is basically a constant value, possibly with a complex structure. Being a constant,
the values of its properties may not change. As such, literals do not have their own
identifiers and cannot stand alone as objects: they are embedded in objects and cannot be
individually referenced. Literal types are decomposed as atomic, collections, structured, or
null. Structured literals contain a fixed number of named heterogeneous elements. Each
element is a pair, where value may be any literal type. For example, we
could define a structure Address as follows: