Referring to example numbers in tcolorbox

Question

In a question I asked before, I implemented method 2 by feculededentier. However, now I am facing difficulty in referring to different examples in this case. For example, what should be the Latex code for "as shown in Example 1.2"?

Answer 1

You have to slightly change the definition. Make it 2 arguments with first one as optional:

\newtcolorbox[auto counter, number within=chapter, number freestyle={\noexpand\thechapter.\noexpand\arabic{\tcbcounter}}]{myexample}[2][]{%
    enhanced,
    breakable,
    fonttitle=\bfseries,
    title=Example~\thetcbcounter: #2,
    #1
}

And then use the label=<name> key like

\begin{myexample}[label=second]{Second example}

Now you can use Example~\ref{second} to refer to these boxes.

Full example (taken and modified from the answer linked in the question)

\documentclass{book}
\usepackage{tcolorbox}
    \tcbuselibrary{skins,breakable}
\usepackage{lipsum}
\newtcolorbox[auto counter, number within=chapter, number freestyle={\noexpand\thechapter.\noexpand\arabic{\tcbcounter}}]{myexample}[2][]{%
    enhanced,
    breakable,
    fonttitle=\bfseries,
    title=Example~\thetcbcounter: #2,
    #1
}
\begin{document}
\chapter{First chapter}
\begin{myexample}[label=first]{First example}
  \lipsum[4]
\end{myexample}
\begin{myexample}[label=second]{Second example}
  \lipsum[4]
\end{myexample}
\chapter{Second chapter}
\begin{myexample}[label=third]{Third example}
  \lipsum[4]
\end{myexample}
From Example~\ref{second} we get some idea.
\end{document}

cleveref version:

You can load cleveref package and use crefname in the options to reduce typing.

\documentclass{book}
\usepackage{cleveref}
\usepackage{tcolorbox}
    \tcbuselibrary{skins,breakable}
\usepackage{lipsum}
\newtcolorbox[auto counter, number within=chapter, 
    crefname={example}{examples},
    Crefname={Example}{Examples},
    number freestyle={\noexpand\thechapter.\noexpand\arabic{\tcbcounter}}]
    {myexample}[2][]{%
    enhanced,
    breakable,
    fonttitle=\bfseries,
    title=Example~\thetcbcounter: #2,

    #1
}
\begin{document}
\chapter{First chapter}
\begin{myexample}[label=first]{First example}
  \lipsum[4]
\end{myexample}
\begin{myexample}[label=second]{Second example}
  \lipsum[4]
\end{myexample}
\chapter{Second chapter}
\begin{myexample}[label=third]{Third example}
  \lipsum[4]
\end{myexample}
\Cref{second} gives us some idea as seen from \cref{first}.
\end{document}