# listbox

Displays a list box, and ask an item to user.

    listbox <message> <title> <string array> [<selected>]

## Parameters

string <message>
  It is displayed in the list box.
string <title>
  It is displayed as the list box title.
array <string array>
  It is displayed as the list box items.
integer <selected> (version 4.89 or later)
  It is selected firt item by specifying the zero-based index of the array. This argument is optional.

## Return Value

System variable <result>
  If the user selects one of items, it is set to from 0 to N-1.
  If the user cancels, it is set to -1.

## Remarks

The listbox macro command shows all selected items of the <string array> array.
If the <string array> is defined as bigger entries than selected numbers as follows, the empty string will be shown at last.

    strdim msg 4
    msg[0] = 'Banana'
    msg[1] = 'Apple'
    msg[2] = 'Orange'
    listbox 'Select your favorite food.' 'Confirmation' msg

    ; displays 4 items
    Banana
    Apple
    Orange
    [Empty string]

(version 4.89 or later)
When the <selected> parameter is specified, an item of the list box can be selected at first.
If the parameter is omitted, the default value is 0.

## Example

    strdim msg 3
    msg[0] = 'Banana'
    msg[1] = 'Apple'
    msg[2] = 'Orange'
    listbox 'Select your favorite food.' 'Confirmation' msg
    sprintf2 var "%d" result
    messagebox var "result"
    ; result
    ;   -1: Cancel
    ;    0: Banana
    ;    1: Apple
    ;    2: Orange

    strdim msg 7
    msg[0] = 'Sunny'
    msg[1] = 'Cloudy'
    msg[2] = 'Rainy'
    msg[3] = 'Windy'
    msg[4] = 'Snowy'
    msg[5] = 'Foggy'
    msg[6] = 'Unknown'
    ; The seventh entry is selected by default.
    listbox "How's today's weather?" 'Confirmation' msg 6
    sprintf2 var "%d" result
    messagebox var "result"

## See also

- yesnobox