Makale
11/18/2011

Strings.Format Method

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

Returns a string formatted according to instructions contained in a format String expression.

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

Syntax

'Declaration
Public Shared Function Format ( _
    Expression As Object, _
    Style As String _
) As String

public static string Format(
    Object Expression,
    string Style
)

Parameters

Expression
Type: System.Object
Required. Any valid expression.

Style
Type: System.String
Optional. A valid named or user-defined format String expression.

Return Value

Type: System.String
Returns a string formatted according to instructions contained in a format String expression.

Remarks

If you are formatting a nonlocalized numeric string, you should use a user-defined numeric format to ensure that you get the look you want.

The String.Format method also provides similar functionality.

For information on how to create the Style argument, see the appropriate topic listed below:

To format	Do this
Numbers	See Predefined Numeric Formats or User-Defined Numeric Formats in the Visual Basic documentation..
Dates and times	See Predefined Date/Time Formats or User-Defined DateTime Formats in the Visual Basic documentation.
Date and time serial numbers	Use date and time formats or numeric formats.

If you try to format a number without specifying Style, the Format function provides functionality similar to the Str function, although it is internationally aware. However, positive numbers formatted as strings using the Format function don't include a leading space reserved for the sign of the value; those converted using the Str function retain the leading space.

Examples

This example shows various uses of the Format function to format values using both String formats and user-defined formats. For the date separator (/), time separator (:), and the AM/PM indicators (t and tt), the actual formatted output displayed by your system depends on the locale settings the code is using. When times and dates are displayed in the development environment, the short time format and short date format of the code locale are used.

Note:
For locales that use a 24-hour clock, the AM/PM indicators (t and tt) display nothing.

Dim TestDateTime As Date = #1/27/2001 5:04:23 PM#
Dim TestStr As String
' Returns current system time in the system-defined long time format.
TestStr = Format(Now(), "Long Time")
' Returns current system date in the system-defined long date format.
TestStr = Format(Now(), "Long Date")
' Also returns current system date in the system-defined long date 
' format, using the single letter code for the format.
TestStr = Format(Now(), "D")

' Returns the value of TestDateTime in user-defined date/time formats.
' Returns "5:4:23".
TestStr = Format(TestDateTime, "h:m:s")
' Returns "05:04:23 PM".
TestStr = Format(TestDateTime, "hh:mm:ss tt")
' Returns "Saturday, Jan 27 2001".
TestStr = Format(TestDateTime, "dddd, MMM d yyyy")
' Returns "17:04:23".
TestStr = Format(TestDateTime, "HH:mm:ss")
' Returns "23".
TestStr = Format(23)

' User-defined numeric formats.
' Returns "5,459.40".
TestStr = Format(5459.4, "##,##0.00")
' Returns "334.90".
TestStr = Format(334.9, "###0.00")
' Returns "500.00%".
TestStr = Format(5, "0.00%")

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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