(1). String and StringBuffer objects! (2). String class common method: Length (), Charat (), Getchars (), Equals () () () () () () () () (), LaseIndex () () (), LaseIndex () () (), LaseIndex () (), Contact () (), valueof (). (3). StringBuffer class: Length (), Capacity (), setLength () (), Charat (), getchars (), append (), INSERT (), Reverse (), Replace (), delete (), deletecharat (), subString () Note the same and different methods of the same and different methods, but how different methods are used!
