When a .java file is compiled into a .class file, any String literals are noted in a special way, just as all constants are. When a class is loaded (note that loading happens prior to initialization), the JVM goes through the code for the class and looks for String literals. When it finds one, it checks to see if an equivalent String is already referenced from the heap. If not, it creates a String instance on the heap and stores a reference to that object in the constant table. Once a reference is made to that String object, any references to that String literal throughout your program are simply replaced with the reference to the object referenced from the String Literal Pool.
In this case, we actually end up with a slightly different behavior because of the keyword "new." In such a case, references to the two String literals are still put into the constant table (the String Literal Pool), but, when you come to the keyword "new," the JVM is obliged to create a new String object at run-time, rather than using the one from the constant table.
I suspect you are wrong on this one - I may try looking at the bytecode to confirm this later if I have time, but I believe that there should be three strings here:"%s %s"String.format("%s %s", "Naseem", "Khan"); [I think-I have never tried this one]
The Sun Certified Java Developer Exam with J2SE 5: paper version from Amazon, PDF from Apress, Online reference: Books 24x7 Personal blog
The Sun Certified Java Developer Exam with J2SE 5: paper version from Amazon, PDF from Apress, Online reference: Books 24x7 Personal blog
The Sun Certified Java Developer Exam with J2SE 5: paper version from Amazon, PDF from Apress, Online reference: Books 24x7 Personal blog