substring confusion...

[sonir shah]

    public class Test023
    {
        public static void main(String args[])
        {
            String str = new String("Hello");        
            System.out.print(str.substring(0,3));        
            System.out.print(" ");        
            System.out.println(str.replace('r', 'h'));
        }
    }

Options :
A: Hell Hello
B: Hel Hel
C: Hel Hello
D: Hell Hell
Answer : c)It will print Hel Hello
I cannot understand from where did this Hello come from.
and where is 'r' in Hello??
please explain
Sonir

[Arsho, Ayan]

its very simple
1) what does this result in
System.out.print(str.substring(0,3));

It will result in Hel since starting point is 0 and count upto 3 characters(remember the first element in indexed 1)

2)System.out.println(str.replace('r', 'h'));
after this is executed there is no match and the same string is retturned
so it is Hello refer to API for more details.
-A