# Keyword Reference

# Default

Keyword value to use in function call.

$var = Default

## Remarks

This keyword should not be used in a general computation expression. AutoIt will not detect such situations because it has too much of a performance penalty.
When used in parameter passing, the behavior is specified in the corresponding AutoIt function documentation.
For UDF's, it is the scripter's responsibility to check if the parameter has been set to Default and to perform the desired behavior in this situation.
If used, the passed parameter will be set to the Default keyword and not to an optional parameter value, if defined.

## Related

IsKeyword, Null

## Example

    #include <MsgBoxConstants.au3>

    Example(Default, Default)

    Func Example($vParam1 = Default, $vParam2 = "Two", $vParam3 = Default)
        If $vParam1 = Default Then $vParam1 = "One" ; If the Default keyword is used, the assign the variable as "One"
        If $vParam3 = Default Then $vParam3 = "Three" ; If the Default keyword is used, the assign the variable as "Three"

        ; Display the following parameters passed to the function.
        MsgBox($MB_SYSTEMMODAL, "Paramaters", "1 = " & $vParam1 & @CRLF & _
                "2 = " & $vParam2 & @CRLF & _
                "3 = " & $vParam3)
    EndFunc   ;==>Example