6.3 Code chunks

Both R markdown and Quarto can use the following ways to specify chunk options:

Use tag=value in the chunk header ```{r}.

```{r my-label, fig.cap = caption}

# R code
```

Alternatively, you can write chunk options in the body of a code chunk after #|, e.g.,

```{r}
#| label: fig-my-label
#| fig-cap: caption 

# R code
```

tag: value is the YAML syntax.

Options format:

space after #| and colon :
Logical values in YAML can be any of: true/false, yes/no, and on/off.
- They all equivalent to TRUE/FALSE (uppercase) in Rmd.
- Note that TRUE/FALSE need to be in uppercase in Rmd.

Note that Quarto accepts Rmd’s way of specifying chunk options. The difference is that Quarto’s label for figures must start with fig-, while Rmd accepts any labels.

```{r label = "fig-my-label", fig.cap = caption}

# R code
```

❗️ Note that NOT all Rmd chunk options are supported in Quarto. See Quarto Chunk Options for all available options.

Quarto chunk options available for customizing output include:

Option	Description
`eval`	Evaluate the code chunk (if `false`, just echos the code into the output).
`echo`	Include the source code in output
`output`\(^{[1]}\)	Include the results of executing the code in the output (`true`, `false`, or `asis` to indicate that the output is raw markdown and should not have any of Quarto’s standard enclosing markdown).
`warning`	Include warnings in the output.
`error`	Include errors in the output (note that this implies that errors executing code will not halt processing of the document).
`include`	Catch all for preventing any output (code or results) from being included (e.g. `include: false`suppresses all output from the code block).
`renderings`	Specify rendering names for the plot or table outputs of the cell, e.g. `[light, dark]`

\(^{[1]}\) output is similar to results in Rmd. You cannot use results='hide' in Quarto, use output: false instead.