What is reifiable and non-reifiable java

What is reifiable and non-reifiable java ?

a reifiable type is one whose runtime representation contains same information than its compile-time representa-tion

a non-reifiable type is one whose runtime representation contains less information than its compile-time representa-tion

Arrays are reifiable as arrays remains as it is at runtime While generic information attached with List is erased at runtime by erasures

So List<String> list=new ArrayList<String>

at runtime will be

List list=new ArrayList();

all generic information is erased. This is done to support the legacy code that is written without using generics.

But in case of arrays

Object[] ojb=new Object[0]

will remain the same at runtime as well. Generics are not mixed with arrays.