Visual Basic 2017 Lesson 20: The Format Functions

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20.1 Format function for Numbers

The Format function in Visual Basic 2017 is a very useful formatting function. It is used to display numbers customised by the programmer. 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 2017 is given in Table 20.1.

Table 20.1

Style argument	Explanation	Example
General Number	To display the number without having separators between thousands.	Format(8972.234, “General Number”)=8972.234
Fixed	To display the number without having separators between thousands and rounds it up to two decimal places.	Format(8972.2, “Fixed”)=8972.23
Standard	To display the number with separators or separators between thousands and rounds it up to two decimal places.	Format(6648972.265, “Standard”)= 6,648,972.27
Currency	To display the number with the dollar sign in front, has separators between thousands as well as rounding it up to two decimal places.	Format(6648972.265, “Currency”)= $6,648,972.27
Percent	Converts the number to the percentage form and displays a % sign and rounds it up to two decimal places.	Format(0.56324, “Percent”)=56.32 %

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

Figure 20.1

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

Table 20.2

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 2017 , we can format date and time using predefined formats or user-defined formats. The predefined formats of date and time are shown in Table 19.3

Table 20.3

Format	description
Format(Now, “General Date”)	Displays current date and time
Format(Now, “Long Date”)	Displays current date in long format
Format (Now, “Short date”)	Displays current date in short format
Format (Now, “Long Time”)	Displays current time in long format.
Format (Now, “Short Time”)	Displays current time in short format.

 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

Figure 20.3

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

Beside 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)

Table 20.4

Format	Description
Format (Now, “m”)	Displays current month and date
Format (Now, “mm”)	Displays current month in double digits.
Format (Now, “mmm”)	Displays abbreviated name of the current month
Format (Now, “mmmm”)	Displays full name of the current month.
Format (Now, “dd/mm/yyyy”)	Displays current date in the day/month/year format.
Format (Now, “mmm,d,yyyy”)	Displays current date in the Month, Day, Year Format
Format (Now, “h:mm:ss tt”)	Dispalys current time in hour:minute:second format and show am/pm
Format (Now, “MM/dd/yyyy h:mm:ss)	Dispalys current date and time in hour:minute:second format

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