How to create a table in Rstudio presentation - r

Question

I'm trying to create a table in an RStudio .Rpres file. Below is what I have at this point from online searching but the alignment is not correct. Is this the best method? Any suggestions on the alignment?
Test
=========================================================
| Right | Left | Default | Center |
|------:|:-----|---------|:------:|
| 12 | 12 | 12 | 12 |
| 123 | 123 | 123 | 123 |
| 1 | 1 | 1 | 1 |
: Demonstration of simple table syntax.
Result:

Answer 1

You can use knitr::kable to print your data.frame
Test
========================================================
```{r, echo=FALSE}
my_df <- iris
knitr::kable(head(my_df))
```
#alignments:
I tried using align = c('l', 'r', 'c', 'r', 'l') as described in ?kable
but it did not work. Maybe this is a bug.
Output of
knitr::kable(head(iris), align = c('l', 'r', 'c', 'r', 'l'))
|Sepal.Length | Sepal.Width| Petal.Length | Petal.Width|Species |
|:------------|-----------:|:------------:|-----------:|:-------|
|5.1 | 3.5| 1.4 | 0.2|setosa |
|4.9 | 3.0| 1.4 | 0.2|setosa |
|4.7 | 3.2| 1.3 | 0.2|setosa |
|4.6 | 3.1| 1.5 | 0.2|setosa |
|5.0 | 3.6| 1.4 | 0.2|setosa |
|5.4 | 3.9| 1.7 | 0.4|setosa |

Answer 2

A pander example:
```{r}
df <- replicate(3, sample(letters, 3))
colnames(df) <- rep('foobar', 3)
pander::pander(df, justify = c('right', 'left', 'center'))
```
Or specifying a global alignment for all columns (which can be a smart function as well BTW):
```{r}
set.alignment('right')
pander::pander(df)
```
Both results in a correctly formatted markdown table that renders fine in HTML.

Answer 3

I managed to get align to work by including the format = "html" parameter in the function call, so in the example discussed above by FlooO:
knitr::kable(head(iris), format = "html", align = c('l', 'r', 'c', 'r', 'l'))
gave me the desired result