This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
in case of first SOP i.e System.out.println("Hello World! :: "+ s1==s2); comparing is made like this : (("Hello World! :: "+ s1) == s2 which will return you false. If you keep the s1==s2 in braces you will get the desired result: System.out.println("Hello World! :: "+ (s1==s2));