How to show the error message in Knit html output?

[Tung]

Hello, I am writing codes in .Rmd file, and I want to see the output file in Knit html form. I have a wrong code and want to show it is wrong.

Error: unexpected input in "3 <- 3 & 5 ！"

I want to show what it is in my output. How should I do?

[AlexisW]

Include this option for the chunk:

```{r error = TRUE}
3 <- 3 & 5 ！
```

See here for more information:

@Yihui

error : ( TRUE ; logical) Whether to preserve errors (from stop() ). By default, the code evaluation will not stop even in case of errors! If we want to stop on errors, we need to set this option to FALSE . Note that R Markdown has changed this default value to FALSE . When the chunk option include = FALSE , knitr will stop on error, because it is easy to overlook potential errors in this case.

(emphasis mine)