Java compiler/interpreter

Question

Why we do we say that Java is a compiled and interpreted language?

What is the advantage of this (being compiled and interpreted)?

Answer 1

Java is considered a "compiled" language because code is compiled into bytecode format that is then run by the Java Virtual Machine (JVM). This gives several advantages in the realm of performance and code optimization, not to mention ensuring code correctness.

It is considered an "interpreted" language because, after the bytecode is compiled, it is runnable on any machine that has a JVM installed. It is in this way that Java is much like an interpreted language in that, for the most part, it doesn't depend on the platform on which is is being run. This behavior is similar to other interpreted languages such as Perl, Python, PHP, etc.

One theoretical downside to the fact that Java programs can be run on any system in absence of the source code is that, while this method of distribution ensures cross-platform compatibility, the developers have one less reason to release their source code, driving a wedge between the ideological meanings of the phrases "cross-platform" and "open source".