Given a list of item in Beamer how to bold and unbold item one at a time?

Question

I want to display the following sentences one at a time in a \begin{item}

However, I want them to bold and unbold one sentence at a time.

For example, I want to display

• Hello World
• Hello Earth
• Hello Sun

The audience should see

• Hello \textbf{World}

then,

• Hello World
• Hello \textbf{Earth}

then,

• Hello World
• Hello Earth
• Hello \textbf{Sun}

and finally,

• Hello World
• Hello Earth
• Hello Sun

Is there a way to achieve this?

Answer 1

I believe this question has been answered here

Shorthand overlay specifications for bold text

But just to give a quick rundown, to get what youre looking for you would have your list written as

\documentclass{beamer}

\begin{document}
    \begin{frame}
        \begin{itemize}[<+-| alert@+>]
            \setbeamercolor{alerted text}{fg=black} %change the font color
            \setbeamerfont{alerted text}{series=\bfseries} %make alerted text bold
            \item<1-> Hello \alert<+>{World}
            \item<2-> Hello \alert<+>{Earth}
            \item<3-> Hello \alert<+>{Sun}
        \end{itemize}
        \uncover<+>{} %make the list all change to unbolded
    \end{frame}
\end{document}

Make sure to include the empty \uncover command, otherwise the last item will remain bolded.

If instead you wanted the entire line to be bolded, you could instead do it as

\documentclass{beamer}

\begin{document}
    \begin{frame}    
        \begin{itemize}[<+-| alert@+>]
            \setbeamercolor{alerted text}{fg=black} %change the font color
            \setbeamerfont{alerted text}{series=\bfseries} %make alerted text bold
            \item Hello World
            \item Hello Earth
            \item Hello Sun
        \end{itemize}
        \uncover<+>{} %make the list all change to unbolded
    \end{frame}
\end{document}