Differences between the C++ Standard Template Library (STL) and the Java
Collections Framework (JCF) include the following:
STL uses template classes and functions which have type parameters.
In the JCF, the collection classes provide collections of Objects.
In Java, there is no way to create a general collection in which all of the
elements have the same type. Instead, the collections are all collections
of objects. These collections can hold objects of any type, and there is
no way for the compiler to verify that all of the objects that are put in
the collection are of the same type. With template classes it is possible
to design a general collection in which all of the elements are of the
same type and for which the compiler can enforce that only objects of the
correct type are added to the collection.
the Java programmer must provide class casts when removing the
objects from the collections. In this case, type errors are not caught
until runtime, when they show up as class cast exceptions.
STL include performance as part of the interface requirements. This is not
normally the case for java collections.
In Java, the algorithms are organized by container, while in STL the
algorithms are independent of the container on which they operate.
STL uses value semantics so that assignment copies a collection.
Java uses reference semantics and assignment simply assigns a reference.
Java collections always contain pointers to objects, while STL collections can
contain pointers to objects or the objects themselves.
STL iterators differ from those in Java. STL has a hierarchy of
iterators which different capabilities, including moving either only
forward or moving forward and backward, and providing random access to
container elements. Container classes are characterized by the iterators
that they provide, and generic algorithms are characterized by the
iterators that they use. Iterators in STL have values that can be
compared. Java only provides Iterator and ListIterator. Random
access iterators are not provided, and interators do not have values that
can be compared.
Java relies heavily on interfaces which do not exist in C++
In STL, containers can contain either objects or objects of primitive
types, and many algorithms operate on either containers or arrays. In
Java, containers contain only objects, and algorithms must be defined
separately for containers and for arrays.
The memory allocation model is part of the STL framework and the STL
programmer needs to be aware of deallocating memory. Neither of these are
concerns in the JCF.
C++ allows passing functions as parameters which is not allowed in