Articolo
11/18/2011

Interaction.Choose Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Selects and returns a value from a list of arguments.

Namespace: Microsoft.VisualBasic
Assembly: Microsoft.VisualBasic (in Microsoft.VisualBasic.dll)

Syntax

'Declaration
Public Shared Function Choose ( _
    Index As Double, _
    ParamArray Choice As Object() _
) As Object

public static Object Choose(
    double Index,
    params Object[] Choice
)

Parameters

Index
Type: System.Double
Required. Double. Numeric expression that results in a value between 1 and the number of elements passed in the Choice argument.

Choice
Type: array<System.Object[]
Required. Object parameter array. You can supply either a single variable or an expression that evaluates to the Object data type, to a list of Object variables or expressions separated by commas, or to a single-dimensional array of Object elements.

Return Value

Type: System.Object
Selects and returns a value from a list of arguments.

Remarks

The Choose function returns a member of the list passed in Choice(), based on the value of Index. The first member of the list is selected when Index is 1. The last member of the list is selected when Index is UBound(Choice()). If Index is outside these limits, Choose returns Nothing.

If Index is not a whole number, it is rounded to the nearest whole number before being evaluated.

You can use Choose to look up a value in a list of possibilities.

Note:
The expressions in the argument list can include function calls. As part of preparing the argument list for the call to Choose, the Visual Basic compiler calls every function in every expression. This means that you cannot rely on a particular function not being called if a different expression is selected by Index.

Examples

This example uses the Choose function to display a name in response to an index passed into the procedure in the Ind parameter.

Function GetChoice(ByVal Ind As Integer) As String
    GetChoice = CStr(Choose(Ind, "Speedy", "United", "Federal"))
End Function

Version Information

Silverlight

Supported in: 5, 4, 3

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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