This function powers
pull() and various functions of the tidyr
package. It is similar to
select_vars() but returns only one
column name and has slightly different semantics: it allows
negative numbers to select columns from the end.
select_var(vars, var = -1)
A character vector of existing column names.
A variable specified as:
The default returns the last column (on the assumption that's the column you've created most recently).
This argument is taken by expression and supports quasiquotation (you can unquote column names and column positions).
The selected column name as an unnamed string.
# It takes its argument by expression: select_var(letters, c)#>  "c"# Negative numbers select from the end: select_var(letters, -3)#>  "x"# You can unquote variables: var <- 10 select_var(letters, !! var)#>  "j"