::: {.cell hash='02_R_introduction_cache/pdf/unnamed-chunk-8_e0b275d3c17e7c3f8d043990e2ab9e90'}

```{.r .cell-code}
x  
# this is a valid name
descriptive_name   
# descriptive names are preferable
# - note the underscore separating the words
# - spaces are not allowed
also.valid  
# This is also a valid name, using an older and maybe
# confusing naming scheme. If you come from Java/C++/Python/Javascript....
# the . in the middle of the name is *not* the member access operator
```
:::