question: private static String unescape ( String s ) { int len = s . length ( ) , base = 0 , idx ; String escapes = "tnrbf\\\"'" ; String chars = "\t\n\r\b\f\\\"'" ; StringBuffer sbuf = null ; while ( ( idx = s . indexOf ( '\\' , base ) ) != - 1 ) { if ( sbuf != null ) sbuf . append ( s . substring ( base , idx ) ) ; if ( idx + 1 == len ) break ; char c = s . charAt ( idx + 1 ) ; int cidx = escapes . indexOf ( c ) ; if ( cidx == - 1 ) { sbuf . append ( '\\' ) ; sbuf . append ( c ) ; } else { if ( sbuf == null ) sbuf = new StringBuffer ( s . substring ( base , idx ) ) ; sbuf . append ( chars . charAt ( cidx ) ) ; } base = idx + 2 ; } if ( sbuf != null && base < len ) sbuf . append ( s . substring ( base ) ) ; return ( sbuf == null ? s : sbuf . toString ( ) ) ; }
target:  Replace escape sequences with represented characters. This includes newlines, tabs, and quotes.