The "-version" option simply causes the JRE version to be printed; it does not cause any change in the way the JRE works.
I think -version option does more than that
From java command
JREs are backwards-compatible: anything that ran on 1.3 should also run on 5.
JRE 5 does not have assured compatibility with 1.3. I tried my code(its a legacy code with heavy swing/awt use) compiled on 1.3.1_19 to run on 1.5 but it gives me wired exceptions.
-version option gives a way to run code compiled with olderversion to run on latest version. I tried doing it eclipse and was successful . however I want to so similar thing on command prompt.
Thanks