question: public static String javaScriptUnescape ( String s ) { StringBuilder sb = new StringBuilder ( s . length ( ) ) ; for ( int i = 0 ; i < s . length ( ) ; ) { char c = s . charAt ( i ) ; if ( c == '\\' ) { i = javaScriptUnescapeHelper ( s , i + 1 , sb ) ; } else { sb . append ( c ) ; i ++ ; } } return sb . toString ( ) ; }
target:  Undo escaping as performed in javaScriptEscape(.) Throws an IllegalArgumentException if the string contains bad escaping.