What is Java extension?

Answer 1

. java is used as an extension but to run that in cmd one has to generate class file else you will get an error as no class. to generate class file javac space the file which you were created. java will create. class file.
ex:my javaprogram name is given as first.java to compile that first we should generate class file
javac first.java later java space program name which means java space first. output will be shown