Q: Problem with referring to a paragraph I have paragraphs in my Appendix, which I have labeled them like this:
\documentclass[12pt,draftclsnofoot,journal,onecolumn]{IEEEtran}
\begin{document}
  See Appendix~\ref{p.1}
  See Appendix~\ref{p.2}
\appendix

\paragraph{par1}\label{p.1}

Content of paragraph 1

\paragraph{par2}\label{p.2}

Content of paragraph 2
\end{document}

I have also used the packages  mathtools, ifpdf,  amsthm ,amsmath, cite, amsfonts, url, amssymb, inputenc, lipsum, and hyperref.
The output is

See Appendix 0.a
See Appendix 1.b
Appendix
a.par1
Content of paragraph 1
b.par2
Content of paragraph 2

How can I get?:

See Appendix A
See Appendix B
Appendix
A.par1
Content of paragraph 1
B.par2
Content of paragraph 2

One way is to use \subsection instead of \paragraph, but it is a waste of space and I have a space limit, since using \subsection makes you write the content of that subsection from the line after the title line. However, when you use \paragraph, you can write the content of the paragraph on the title line. Any idea?

A: I don't recommend this because it might be rejected by IEEETran editors etc. 
The \theparagraph macro has multiple definitions, depending on class options, but the easiest way is to use \renewcommand{\theparagraph}{\Alph{paragraph}} after `\appendix.
However, the number in the paragraph header is set with \@seccntformat which uses \def\@seccntformat#1{\csname the#1dis\endcsname\hskip 0.5em\relax} where \theparagraphdis is defined somewhere in the .cls file, having different meanings depending (again) on the class options. 
\documentclass[12pt,draftclsnofoot,journal,onecolumn]{IEEEtran}


\begin{document}

  See Appendix~\ref{p.1}

  See Appendix~\ref{p.2}

\appendix
\makeatletter
\renewcommand{\theparagraph}{\Alph{paragraph}}% Redefine the output of the `paragraph` counter to use upper case (\Alph)` letters
 % Redefine `\@seccntformat` to use `\the...` and not `\the...dis`. 
\renewcommand{\@seccntformat}[1]{\csname the#1\endcsname.\quad}
%Alternatively use 
%\let\theparagraphdis\theparagraph
\makeatother


\paragraph{Paragraph one}\label{p.1}

Content of paragraph 1

\paragraph{Paragraph two}\label{p.2}

Content of paragraph 2
\end{document}


