check_one_colnames: Check that at least one name is among column names
Description
Check that at least one name is among column names
Usage
check_one_colnames(df, x, null_ok = TRUE, qualifier = NULL)
Value
invisible NULL or a string if the criteria are not fulfilled.
Arguments
- df
(data.frame)
- x
(character) the names of the columns to be checked.
- null_ok
(flag) can x be NULL.
- qualifier
(string) to be returned if the check fails.