line break in markdown code example

Example 1: line break in code in markdown

// Add two spaces at the end of the line

This is my first line.   (<-- two spaces)
This is my second line.

Example 2: Markdown new line

Hello  (<-- two spaces)
World

Example 3: markdown break line rstudio

blablabla [2 x Space, 1 x return] is equivalent to <br />
next line ...