Removing spaces from label generated inside command based on arguments

Question

I have a command which takes two arguments. Inside the command there will be inserted a subsection which also would like to put a label on. The problem is that the arguments might have Spaces between the Words and therefore thay have to be removed before assigning them to the label.

A MCE looks like this:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{hyperref}

\newcommand{\createPerson}[2]
{
    \subsection{#1}
    \label{#1#2}
    Use of the original #1 and #2 again.
}

\begin{document}
    \createPerson{Hans Viggo Jensen}{1956}

    See the reference \ref{HansViggoJensen1956}, \nameref{HansViggoJensen1956}.
\end{document}

Answer 1

Don't do it. Don't do it.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{hyperref}

\makeatletter
\newcommand{\createPerson}[2]{%
  \subsection{#1}%
  \label{\zap@space#1 \@empty #2}%
  Use of the original #1 and #2 again.
}
\makeatother

\begin{document}

\createPerson{Hans Viggo Jensen}{1956}

See the reference \ref{HansViggoJensen1956}, \nameref{HansViggoJensen1956}.

\end{document}

But then try this with

Preben Elkjær Larsen

and you will understand why you should never do this.

And no, leaving the spaces in the argument to \ref and your unmodified code won't do either.

Labels should be just easy mnemonics. In case your references are mostly without special letters, you can obviate to the problem by adding an optional argument:

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{xparse}
\usepackage{hyperref}

\ExplSyntaxOn

\tl_new:N \l_firefly_label_tl

\NewDocumentCommand{\createPerson}{omm}
 {
  \IfValueTF{#1}
   {% use the optional argument, if present
    \tl_set:Nn \l_firefly_label_tl { #1 #3 }
   }
   {% otherwise, strip spaces
    \tl_set:Nn \l_firefly_label_tl { #2 #3 }
    \tl_replace_all:Nnn \l_firefly_label_tl { ~ } { }
   }
  \subsection{#2}
  \label{\l_firefly_label_tl}
  Use ~ of ~ the ~ original ~ #2 ~ and ~ #3 ~ again.
}
\ExplSyntaxOff

\begin{document}

\createPerson{Hans Viggo Jensen}{1956}

See the reference \ref{HansViggoJensen1956}, \nameref{HansViggoJensen1956}.

\createPerson[PrebenElkiaerLarssen]{Preben Elkjær Larssen}{2015}

See the reference \ref{PrebenElkiaerLarssen2015}, \nameref{PrebenElkiaerLarssen2015}

\end{document}

I'm not really sure this will ease your typing, but you're the best judge.