I checked the version of eclipse in "About eclipse" link under help tab and it says "Eclipse IDE for Java EE developers 220.127.116.1100617-0521"
So is this version 3 or earlier version ? In java 1.2 means Java2 and 1.4 means java 4.
When I check the details of this IDE, eclipse platform version is 3.6.0.I20100608-0911 and Java EE IDE is 18.104.22.16800617-0521
1) Does this mean that ecliplse version we are using is 3.6 and Java EE version is 1.3 ? Does eclipse come with java preinstalled or does it require to have Java installed on computer ? If eclipse comes with Java, does it mean that, if I dont have Java installed in my environment, still eclipse will compile and run Java source files and class files ?
2) If I have Java 6 installed on my computer, does eclipse use Java 6 or Java 3 for compilation and running of java classes created within eclipse ?
3) Does it mean that there are two versions of Java running on my computer at same time , one in eclipse and other in laptop ?
4) Can I upgrade java version in eclipse ?
1) The number you are seeing is the version number of the EPP package for "Eclipse IDE for Java EE developers". It is not the Eclipse version number, it is not the JDK version number, it is not the J2EE JDK version number either. You need to install a JDK and configure Eclipse to use it. At first start, Eclipse usually looks at JAVA_HOME to set a default JDK.
2) When you create a new project, you can define which JRE to use in the project creation wizard.
4) Yes. You can install as many JDK as you want, and configure which JRE to use in the Project settings.