How many String are created?

Question

public String makinStrings() {
     String s = �Fred�;
     s = s + �47�;
     s = s.substring(2, 5);
     s = s.toUpperCase();
     return s.toString();
}How many objects are created when this method is called?
My answer is 5
1. "Fred"
2. "47"
3. "Fred47"
4. "ed4"
5. "ED4"
But my friend is telling it is 3.
1. "Fred"
2. "47"
3. "Fred47"
I know that any method called on String object creates a brand new String. Please help me with the solution whether it is 3 or 5.

Answer 1

hi,
First of all i want to thanks for all of your replies.
My friend is saying that when we say "How many objects when method is invoked" it means at runtime. String literals are not created at run time.
String s = �Fred�; // No object is creatd here
s = s + �47�; // One object created "s"
s = s.substring(2, 5); //Another object "s"
s = s.toUpperCase(); //Another object "s"
return s.toString();
Hence total 3 objects.
Now the i have got a doubt. Are String literals created at Complie time itself. Or since String s = "Fred" is a compile time constant field. And String literal "47" is also a compile time constant field.
Suppose if the code is like this
String s = new String("Fred")
String s1 = s; ---------------- Then is this String object created at Run time.
String s2 = "47" ----------- This object is created at Complie time.
Please clarify my doubt.