```
my_fun = function(df, filter_var = NULL) {
df %>% {
if(!is.null(filter_var)) {
filter(., Species == filter_var)
}
}%>%
group_by(Species) |>
summarise(n = n())
}
x = my_fun(iris, "setosa")
```
```
my_fun = function(df, filter_var = NULL) {
df %>% {
if(!is.null(filter_var)) {
filter(., Species == filter_var)
}
}%>%
group_by(Species) |>
summarise(n = n())
}
x = my_fun(iris, "setosa")
```