java--container (generic type)

"Generics"

Cause: JDK1.4 before the type is ambiguous <1> the type of the mounted collection is treated as object, thus losing its actual type.  <2> often needs to be transformed when taken out of a collection, inefficient, and prone to error. Workaround: <1> Define the type of the object in the collection at the same time----instance program: list<string> C = new arraylist<string> (); The original cast is an object type, which is not required, and is directly qualified as String type C.add ("AA"); C.add ("BB"); C.add ("CC");      for (int i=0;i<c.size (); i++) {String c = c.get (i); System.out.println (c); Benefits: Enhanced readability and stability of the program

java--container (generic type)