Knowledge Quiz: Chunks and Options

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A Quarto document has two R chunks. The first chunk creates an object called x. Can the second chunk use x, without recreating it?

Yes, because all R chunks in a document share a single, continuous session.Only if the cache: TRUE option is set on the first chunk.No, each chunk runs in its own isolated environment.Only if both chunks have the same label.

• Correct: chunks in the same language run in one shared session, so objects persist across chunks in the order they appear.
• Wrong: caching affects whether a chunk’s computation is rerun on subsequent renders; it isn’t required for objects to be shared within a single render.
• Wrong: R chunks are not isolated from one another.
• Wrong: chunk labels identify chunks for referencing and error messages; they don’t control whether objects are shared.

You copy-paste an existing chunk to use as a starting point for a new one, but forget to change its label. What happens when you render the document?

Rendering fails with a duplicate-label error.Quarto silently renames the second chunk’s label automatically.Nothing; chunk labels are purely cosmetic and don’t affect rendering.Only the first chunk with that label is executed; the second is skipped.

• Correct: chunk labels must be unique within a document; a duplicate causes rendering to fail with an error.
• Wrong: Quarto does not silently rename duplicate labels.
• Wrong: chunk labels must be unique, and duplicates cause a rendering error.
• Wrong: this is not how Quarto handles duplicate labels; rendering fails outright.

You want a chunk’s code to run, but neither the code nor its output should appear anywhere in the rendered document (for example, a setup chunk loading packages). Which option should you use?

eval: FALSEerror: FALSEecho: FALSEinclude: FALSE

• Wrong: eval: FALSE prevents the chunk from running at all, so packages would not actually be loaded.
• Wrong: error: FALSE controls whether rendering stops on an error; it does not hide code or output.
• Wrong: echo: FALSE hides only the code; the result would still appear.
• Correct: include: FALSE runs the chunk but hides both the code and any output.

How does Quarto expect chunk options to be written inside an R chunk?

As plain R function calls at the top of the chunk, e.g. set_echo(FALSE).As arguments inside the curly braces, e.g. {r, echo=FALSE}.As commented lines starting with #|, placed directly below the chunk header.As a separate YAML file referenced by the chunk’s label.

• Wrong: chunk options are not set through R function calls.
• Wrong: this is the older R Markdown syntax; Quarto uses a different convention.
• Correct: Quarto chunk options are written as #| commented lines directly below the chunk header.
• Wrong: chunk options are written inline in the chunk itself, not in a separate file.