on the string "abcdefghijklmnop"operation output length( charat( 'fconcat("qrs""abcdefghijklmnopqrsendswith("javapop"false indexof("ghi" startswith("abcd"true substring( , "efghijwith the exception of the indexof(qmethodwhich we discuss in section all the methods above are easily implemented simply by representing the string as an array of characterswhich is the standard string implementation in java the java stringbuffer class the main methods of the java stringbuffer class are listed belowappend( )return +qreplacing with insert(iq)