I'm ready to take one SCJP, but not sure which one to take. If I take 1.4, maybe will get a high score, but I wonder if 1.2 and 1.4 have the same value since 1.4 seems simpler than 1.2. I hope this exam will help me a little to find a job. Please give me an idea which one is better?
If you can afford it, do the 1.2 then do the upgrade to 1.4 - then you will have both. From experience employers want whatever you dont have. So if you have 1.2 they will probably complain about it being old. And if you have 1.4 they will probably complaing that you dont have any graphics. (And if you have both, they will probably complain that you dont have web, but that is a different problem). Good luck with the job hunting.
You should get a 1.4 book. There are some big differences. Or actually I guess you could stick with the 1.2 and look online for the differences. There is no more awt things and assert statements have been added as well as expanded collections. I'm not sure of the other differences, check out javaranch faq