Built-In Formate Functions
What are the Built-In Formate Functions in VB.NET?
When working with VB.NET, it is important to have a good understanding of the built-in format functions. These functions allow you to format data in a specific way, making it easier to display and work with. In this article, we will explore the various built-in format functions in VB.NET, their syntax, and how to use them in your code.
Introduction
VB.NET is a popular programming language that is widely used to develop Windows-based applications. One of the key features of VB.NET is its ability to format data in a specific way using built-in format functions. These functions allow you to format data such as numbers, currency, dates, and times in a variety of ways.
In this article, we will provide an in-depth explanation of the various built-in format functions in VB.NET, including their syntax and usage examples. By the end of this article, you will have a better understanding of how to use these functions to format your data effectively.
Overview of Built-In Format Functions
There are several built-in format functions in VB.NET that can be used to format data in various ways. These functions are:
- Format
- FormatCurrency
- FormatDateTime
- FormatNumber
- FormatPercent
- FormatString
- FormatTime
- FormatXML
In the following sections, we will take a closer look at each of these functions and provide examples of how they can be used.
The Format Function
The Format function is used to format a value with a specified format. The syntax for the Format function is as follows:
Format(expression[, format[, firstdayofweek[, firstweekofyear]]])
- expression: The value to be formatted.
- format: A string expression that specifies the format to be used. This is an optional parameter.
- firstdayofweek: An optional constant that specifies the first day of the week. This can be any of the following values: vbUseSystemDayOfWeek, vbSunday, vbMonday, vbTuesday, vbWednesday, vbThursday, vbFriday, vbSaturday.
- firstweekofyear: An optional constant that specifies the first week of the year. This can be any of the following values: vbUseSystem, vbFirstJan1, vbFirstFourDays, vbFirstFullWeek.
Here is an advanced code example for the Format function in VB.NET:
Imports System.Globalization
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim myDate As Date = #4/11/2023#
Dim myFormattedDate As String = myDate.ToString("dddd, MMMM d, yyyy", CultureInfo.InvariantCulture)
MessageBox.Show("The formatted date is: " & myFormattedDate)
End Sub
End Class
In this code, the ToString method is used to format the date myDate as a string with the format “dddd, MMMM d, yyyy”, using the CultureInfo.InvariantCulture parameter to ensure that the format is not affected by the current system culture.
To display the formatted date in a message box, you can use the MessageBox.Show method:
Run the app and click the button to check the output as given below.
The FormatCurrency Function
The FormatCurrency function is used to format a value as currency. The syntax for the FormatCurrency function is as follows:
FormatCurrency(expression[, numdigits[, includeleadingzero[, useparens[, groupdigits]]]])
- expression: The value to be formatted.
- numdigits: An optional parameter that specifies the number of digits to display after the decimal point. The default value is the number of digits specified by the system currency format.
- includeleadingzero: A Boolean value that indicates whether to include a leading zero for decimal values between -1 and 1. The default value is False.
- useparens: A Boolean value that indicates whether to enclose negative values in parentheses. The default value is False.
- groupdigits: A Boolean value that indicates whether to use digit grouping. The default value is True.
The FormatCurrency function is used to format a numeric value as a currency string, using the currency symbol and number format of the current system culture. However, you can also specify a specific culture or currency format using the CultureInfo class.
Here are some examples of how to use FormatCurrency for different countries:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim amount As Decimal = 1234.56
Dim formattedAmountusa As String = FormatCurrency(amount, 2, TriState.True, TriState.False, TriState.False)
ListBox1.Items.Add("The formate example for USA Currency is = " & formattedAmountusa)
Dim ukCulture As CultureInfo = CultureInfo.GetCultureInfo("en-GB")
Dim formattedAmountuk As String = amount.ToString("C2", ukCulture)
ListBox1.Items.Add("The formate example for United Kingdom Currency is = " & formattedAmountuk)
Dim japaneseCulture As CultureInfo = CultureInfo.GetCultureInfo("ja-JP")
Dim formattedAmountjapan As String = amount.ToString("C2", japaneseCulture)
ListBox1.Items.Add("The formate example for Japan Currency is = " & formattedAmountjapan)
Dim pkrCulture As CultureInfo = CultureInfo.GetCultureInfo("ur-PK")
Dim formattedAmountpkr As String = amount.ToString("C2", pkrCulture)
ListBox1.Items.Add("The formate example for Pakistan Currency is = " & formattedAmountpkr)
End Sub
Run the app and click the button to see the following output:
The FormatDateTime Function
The FormatDateTime function is used to format a value as a date and/or time. The syntax for the FormatDateTime function is as follows:
FormatDateTime(expression[, dateformat[, firstdayofweek[, firstweekofyear]]])
- expression: The value to be formatted.
- dateformat: An optional parameter that specifies the format to be used. This can be any of the following values: vbGeneralDate, vbLongDate, vbShortDate, vbLongTime, vbShortTime.
- firstdayofweek: An optional constant that specifies the first day of the week. This can be any of the following values: vbUseSystemDayOfWeek, vbSunday, vbMonday, vbTuesday, vbWednesday, vbThursday, vbFriday, vbSaturday.
- firstweekofyear: An optional constant that specifies the first week of the year. This can be any of the following values: vbUseSystem, vbFirstJan1, vbFirstFourDays, vbFirstFullWeek.
The FormatDateTime function is used to format a DateTime value as a string, using a specified date/time format. The DateFormat enumeration provides predefined date/time formats that can be used with this function, but you can also specify a custom format string.
Here are some examples of how to use FormatDateTime for different countries:
Imports System.Globalization
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim usCulture As CultureInfo = CultureInfo.GetCultureInfo("en-US")
Dim myDate As DateTime = DateTime.Now
Dim formattedDateusa As String = myDate.ToString("d", usCulture)
ListBox1.Items.Add("The formated date for USA is = " & formattedDateusa)
Dim ukCulture As CultureInfo = CultureInfo.GetCultureInfo("en-GB")
Dim formattedDateuk As String = myDate.ToString("d", ukCulture)
ListBox1.Items.Add("The formated date for UK is = " & formattedDateuk)
Dim japaneseCulture As CultureInfo = CultureInfo.GetCultureInfo("ja-JP")
Dim formattedDatejapan As String = myDate.ToString("d", japaneseCulture)
ListBox1.Items.Add("The formated date for Japan is = " & formattedDatejapan)
Dim pkrCulture As CultureInfo = CultureInfo.GetCultureInfo("ur-PK")
Dim formattedDatepkr As String = myDate.ToString("d", pkrCulture)
ListBox1.Items.Add("The formated date for Pakistan is = " & formattedDatepkr)
End Sub
End Class
Run the app and check the output:
The FormatNumber Function
The FormatNumber function is used to format a value as a number. The syntax for the FormatNumber function is as follows:
FormatNumber(expression[, numdigits[, includeleadingzero[, useparens[, groupdigits]]]])
- expression: The value to be formatted.
- numdigits: An optional parameter that specifies the number of digits to display after the decimal point. The default value is the number of digits specified by the system number format.
- includeleadingzero: A Boolean value that indicates whether to include a leading zero for decimal values between -1 and 1. The default value is False.
- useparens: A Boolean value that indicates whether to enclose negative values in parentheses. The default value is False.
- groupdigits: A Boolean value that indicates whether to use digit grouping. The default value is True.
Here is an example of how to use the FormatNumber function:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim myValue As Double = 12345.67
Dim myFormattedValue As String = FormatNumber(myValue)
ListBox1.Items.Add("The formated number is = " & myFormattedValue)
End Sub
The output will be as:
In this example, the FormatNumber function is used to format the value 12345.67 as a number. The resulting formatted value would depend on the system number format, but for US English, it would be “12,345.67”.
The FormatPercent Function
The FormatPercent function is used to format a value as a percentage. The syntax for the FormatPercent function is as follows:
FormatPercent(expression[, numdigits[, includeleadingzero[, useparens[, groupdigits]]]])
- expression: The value to be formatted.
- numdigits: An optional parameter that specifies the number of digits to display after the decimal point. The default value is the number of digits specified by the system percentage format.
- includeleadingzero: A Boolean value that indicates whether to include a leading zero for decimal values between -1 and 1. The default value is False.
- useparens: A Boolean value that indicates whether to enclose negative values in parentheses. The default value is False.
- groupdigits: A Boolean value that indicates whether to use digit grouping. The default value is True.
Here is an example of how to use the FormatPercent function:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim myValue As Double = 0.12345
Dim myFormattedValue As String = FormatPercent(myValue, 2)
ListBox1.Items.Add("The formated percent is = " & myFormattedValue)
End Sub
The output is given below:
In this example, the FormatPercent function is used to format the value 0.12345 as a percentage with two decimal places. The resulting formatted value would depend on the system percentage format, but for US English, it would be “12.35%”.
The FormatString Function
The FormatString function is used to format a string by replacing placeholders with values. The syntax for the FormatString function is as follows:
FormatString(format[, arg0[, arg1[, arg2[, arg3[, arg4[, arg5[, arg6[, arg7[, arg8[, arg9]]]]]]]]]])
- format: The format string containing placeholders.
- arg0 – arg9: The values to be inserted into the placeholders.
Here is an example of how to use the FormatString function:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim myString As String = "Hello {0}! Today is {1}."
Dim myFormattedValue As String = String.Format(myString, "John", DateTime.Now.ToShortDateString())
ListBox1.Items.Add(myFormattedValue)
End Sub
Run the app the output is:
In this example, String.Format is used to replace the {0} placeholder with the string “John”, and the {1} placeholder with the current date in short date format. The resulting string is then stored in the myFormattedValue variable.
Conclusion
In this article, we have covered the built-in format functions in VB.NET, including the FormatCurrency, FormatDateTime, FormatNumber, FormatPercent, and FormatString functions. These functions provide a convenient way to format values for display in your applications. By using these functions, you can ensure that your application’s output is formatted consistently and correctly across different systems and cultures.
FAQs
- Q : What is the purpose of the FormatCurrency function in VB.NET?
Ans : The FormatCurrency function is used to format a value as currency.
- Q : How do I use the FormatDateTime function in VB.NET?
Ans : You can use the FormatDateTime function to format a value as a date and/or time.
- Q : What is the syntax for the FormatNumber function in VB.NET?
Ans : The syntax for the FormatNumber function is: FormatNumber(expression[, numdigits[, includeleadingzero[, useparens[, groupdigits]]]])
- Q : What is the difference between the FormatNumber and FormatPercent functions in VB.NET?
Ans : The FormatNumber function is used to format a value as a number, while the FormatPercent function is used to format a value as a percentage.
- Q : Can I use the FormatString function to format strings with multiple placeholders?
Ans : No, FormatString is not a built-in function in VB.NET. To format strings with multiple placeholders, you can use the String.Format method or the composite formatting feature of the String class.
- Q : What is the difference between Format and FormatCurrency functions?
Ans : The Format function is used to format a value as a string according to a specified format, while the FormatCurrency function is used specifically to format currency values as strings.
