Find the length of the set of difference between `x`

and `y`

vectors.

`count_diff(x, y, ignore.case = FALSE)`

## Arguments

- x
A vector to check.

- y
A vector to compare against.

- ignore.case
logical; if `FALSE`

, the pattern matching is case
sensitive and if `TRUE`

, case is ignored during matching.

## Value

The number of *unique* values of `x`

not in `y`

.

## See also

Other counting wrappers:
`count_in()`

,
`count_na()`

,
`count_out()`

,
`na_in()`

,
`na_out()`

,
`na_rep()`

,
`prop_distinct()`

,
`prop_in()`

,
`prop_na()`

,
`prop_out()`

,
`what_in()`

,
`what_out()`

## Examples

```
# only unique values are checked
count_diff(c("VT", "NH", "ZZ", "ZZ", "ME"), state.abb)
#> [1] 1
```