Does the input contain a (non-empty) character string?

isString(x, nullOK = FALSE, .xname = getNameInParent(x))

Arguments

x	Object.
nullOK	`logical(1)`. If set to `TRUE`, `x` may also be `NULL`.
.xname	Name of object defined in `x`. Not intended to be used directly.

Value

TRUE on success; FALSE on failure, with cause set.

Note

Updated 2019-08-10.

Examples

## TRUE ====
isString("hello")
#> [1] TRUE

## FALSE ====
isString(1)
#> [1] FALSE
#> Cause: '1' is not character.
isString("")
#> [1] FALSE
#> Cause: '""' contains empty string.
isString(NA_character_)
#> [1] FALSE
#> Cause: 'NA_character_' is NA.