What do these lines mean?

[coding]

double hours = Convert.toDouble
What does the double mean? What does the convert to double mean
SimpleIO.prompt("What is your age? ");
String userName = SimpleIO.readLine();

Does that specifially tell that line to show up to ask and then show it back. What if it was back to back like?
SimpleIO.prompt("What is your age? ");
String userName = SimpleIO.readLine();
SimpleIO.prompt("Do you have a job? ");
String userName = SimpleIO.readLine();
Will it go one by one?

[doWhile]

Your question is a bit out of context - the Objects references in the code you posted are not part of the standard java SE package. I can speculate as to what they do and try to answer all your questions, but feel pointing you to the java tutorials would be time better spent which, if you invest the time, might answer your questions more thoroughly (and then some).
The Java™ Tutorials

[coding]

Thanks, but I don't really have the time to read and analyze. I'm a fast learner and if someone could just briefly explain it would help.

[doWhile]

Well I'll just be blunt and get straight to the point...

but I don't really have the time to read and analyze.

...if you don't have time to learn, I don't have time to teach.

[sunde887]

If you don't know something as basic as what double means, Id suggest you really take a little bit of time and scan the tutorials, if you are indeed a quick learner, a quick scan should help you understand a decent amount of what the tutorials explain.

[Junky]

Thanks, but I don't really have the time to read and analyze. I'm a fast learner and if someone could just briefly explain it would help.

OK

So there is a whole bunch of information on the net and in books which you cannot be bothered to read. Instead you want someone here to replicate that information just for you. Bite me! Also if you cannot be bothered to read what is already out there then presumably you cannot be bothered to read what anyone types here either.