select.list {utils} | R Documentation

## Select Items from a List

### Description

Select item(s) from a character vector.

### Usage

    select.list(choices, preselect = NULL, multiple = FALSE,
                title = NULL, graphics = getOption("menu.graphics"))

### Arguments

`choices` | a character vector of items.
`preselect` | a character vector, or `NULL`. If non-null and if the string(s) appear in the list, the item(s) are selected initially.
`multiple` | logical: can more than one item be selected?
`title` | optional character string for window title, or `NULL` for no title.
`graphics` | logical: should a graphical widget be used?

### Details

The normal default is `graphics = TRUE`. This brings up a modal dialog box with a (scrollable) list of items, which can be selected by the mouse. If `multiple` is true, further items can be selected or deselected by holding the control key down whilst selecting, and shift-clicking can be used to select ranges.

Normal termination is via the ‘OK’ button or by hitting Enter or double-clicking an item. Selection can be aborted via the ‘Cancel’ button or pressing Escape.

If `graphics` is FALSE or no graphical widget is available it displays a text list from which the user can choose by number(s). The `multiple = FALSE` case uses `menu`. Preselection is only supported for `multiple = TRUE`, where it is indicated by a `"+"` preceding the item.

It is an error to use `select.list` in a non-interactive session.

### Value

A character vector of selected items. If `multiple` is false and no item was selected (or `Cancel` was used), `""` is returned. If `multiple` is true and no item was selected (or `Cancel` was used) then a character vector of length 0 is returned.

### See Also

`menu`, `tk_select.list` for a graphical version using Tcl/Tk.

### Examples

    ## Not run:
    select.list(sort(.packages(all.available = TRUE)))

    ## End(Not run)

[Package utils version 3.5.1 Index]