latex vertical line code example

Example 1: latex line break

# Basic syntax:
\linebreak

# Note use \clearpage to add white space to the end of the page

Example 2: latex matrix vertical line

\left[
	\begin{array}{cccc|c}
		1 & 0 & 3 & -1 & 0 \\
		0 & 1 & 1 & -1 & 0 \\
		0 & 0 & 0 & 0 & 0 \\
	\end{array}
\right]

Example 3: latex vertical space after paragraph

\documentclass{article}
\setlength{\parskip}{\baselineskip}%
\setlength{\parindent}{0pt}%
\begin{document}
Googling didnt give required results.(many, but not applicable or code doesn't work)

Essentially, what I want to do is the same formatting I just did with this question.

I am really sceptical about LaTeX whenever you encounter problem which can't be solved in 30 minutes means that you are unlikely to find correct solution.

What I use at the moment is \verb|'\\\\'|. Being from developers' circle I tend to deal with all kind of warning. These four slashes give me 'badboxes'. How to produce exactly same correct formatting I just did now with this text.

I appreciate your help and not critics. These kind of operations should not be a ritual dance around the fire in the first place.
\end{document}