Difference between Java & C++
1 Platform compatible, write once, run everywhere on JVM.
2 Java compiles to Java byte code and can be recognized by JVM, independedt to underline OS.
3 Interpreter to routines on systems with different machine codes.
4 Strongly encoraged OO programming Paradigm, everything in Java is class/Object
5 All types (reference, primitive types) are always passed by value
6 Java does not supported unsigned integers
7 Pointers vs Reference
a) no pointer arighmetics.
8 No operator overloading
9 Gargabe Collection.
More in Details: to be continued
(1) What is JVM ? Java Virtual Machine
(2) JRE or JDK
-- JRE is the JVM program, Java application need to run on JRD
-- JDK is a superset of JRE, JRE + tools for developing java programs. e.g, it provides the compiler "javac"
原文：http://www.cnblogs.com/tianxiaoxi/p/5120114.html