1) Scanner scan = new Scanner(System.in);
scan.close(); –> close the stream opened
2) difference between Stringbuffer and Stringbuilder
3) find duplicate elements in an array.
4) Solving tower of Hanoi problem using an algorithm
Eclipse useful shortcuts ===>
Ctrl + Shift + T ==> Open Type in Hierarchy
Ctrl + Shift + U ==> Find occurrences of expression in current file
Ctrl + Alt + H ==> Open Call Hierarchy
Ctrl + Shift + R ==> Open Resource (file, folder or project)
