Lesson 20 Format Function

20.1 Format function for Numbers

The Format function in Visual Basic 2015 is a very useful formatting function. It is used to display numbers in formats customized by the users. For example, to display a number with separators or without separators. It can also be used to display date and time in various formats. There are two types of Format functions, the built-in Format function, and the user-defined Format function.

20.1(a) Built-in Format function for Numbers

The syntax of the built-in Format function is

Format (n, “style argument”)

where n is a number.

The list of style arguments in Visual Basic 2015 is given in Table 20.1.

Example 20.1

Private Sub BtnFormat_Click(sender As Object, e As EventArgs) Handles BtnFormat.Click

Label1.Text = Format(8972.234, "General Number")
Label2.Text = Format(8972.2, "Fixed")
Label3.Text = Format(6648972.265, "Standard")
Label4.Text = Format(6648972.265, "Currency")
Label5.Text = Format(0.56324, "Percent")

End Sub

The Output

20.1(b) User-Defined Format

The syntax of the user-defined Format function is

Format (n, “user’s format”)

Although it is known as user-defined format, we still need to follows certain formatting styles. Examples of user-defined formatting style are listed in Table 19.2

Example 20.2

Private Sub BtnFormat_Click(sender As Object, e As EventArgs) Handles BtnFormat.Click

Label1.Text = Format(8972.234, "0.0")
Label2.Text = Format(8972.2345, "0.00")
Label3.Text = Format(6648972.265, "#,##0.00")
Label4.Text = Format(6648972.265, "$#,##0.00")
Label5.Text = Format(0.56324, "0%")

End Sub

The Output

Figure 20.2

20.2 Formatting Date and Time

There are two types of Format functions for Date and time one of them is the built-in or predefined format while another one can be defined by the user.

20.2(a) Formatting Date and time using predefined formats 

In Visual Basic 2013, we can format date and time using predefined formats or user-defined formats. The predefined formats of date and time are shown in Table 20.3

 Example 20.3

Private Sub BtnDisplay_Click(sender As Object, e As EventArgs) Handles BtnDisplay.Click

Label1.Text = Format(Now, "General Date")
Label2.Text = Format(Now, "Long Date")
Label3.Text = Format(Now, "short Date")
Label4.Text = Format(Now, "Long Time") Label5.Text = Format(Now, "Short Time")

End Sub

The output

You can display dates and time in real-time using a timer and set its property Enabled to true and interval 100. The code is as follows:

Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick

Label1.Text = Format(Now, "General Date")
Label2.Text = Format(Now, "Long Date")
Label3.Text = Format(Now, "short Date")
Label4.Text = Format(Now, "Long Time")
Label5.Text = Format(Now, "Short Time")

End Sub

20.2(b) Formatting Date and time using user-defined formats

Besides using the predefined  formats, you can also use the user-defined formatting functions. The syntax of a user-defined format  for date and time is

  Format (expression,style)

Example 20.4

Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick

Label1.Text = Format(Now, "m")
Label2.Text = Format(Now, "mm")
Label3.Text = Format(Now, "mmm")
Label4.Text = Format(Now, "mmmm")
Label5.Text = Format(Now, "dd/mm/yyyy")
Label6.Text = Format(Now, "mmm,d,yyyy")
Label7.Text = Format(Now, "h:mm:ss tt")
Label8.Text = Format(Now, "MM/dd/yyyy h:mm:ss tt")

End Sub

The output