read.and.check(message = "", what = numeric(), lower, upper, answer.in, default)
message
| message displayed before prompting for user input. |
what
|
the type of what gives the type of data to be read.
|
lower
| lower limit of input, for numeric input only. |
upper
| upper limit of input, for numeric input only. |
answer.in
|
the input must correspond to one of the elements of the
vector answer.in , if supplied.
|
default
| value assumed if user enters a blank line. |
what
, lower
, upper
and
answer.in
. If the input does not satisfy all the conditions,
an appropriate error message is produced and the user is prompted
to provide input. This process is repeated until a valid input value
is entered.default
argument is
specified, a blank line is accepted as valid input and in this case
read.and.check
returns the value of default
.