FormatNumber(expression _
        [, digits_after_decimal] _
        [, include_leading_zero] _
        [, use_parens_if_negative] _
        [, groups_digits] )

Where:

expression

The numeric expression to format

digits_after_decimal

The number of digits to display after the decimal point

include_leading_zero

If the number is less than 1 and greater than -1, determines whether the number should have a leading 0 before the decimal point.

use_parens_if_negative

Determines whether negative numbers are surrounded with parentheses instead of using a minus sign.

groups_digits

Determines whether digits to the left of the decimal point are grouped with thousands separators (commas in the United States).

Examples:

Expression	Result
FormatNumber(1.23456, 2)	1.23
FormatNumber(0.123456, 2, TriState.False)	.12
FormatNumber(0.123456, 2, TriState.True)	0.12
FormatNumber(-12345.12, , TriState.False)	-12,345.12
FormatNumber(-12345.12, , TriState.True)	(12,345.12)
FormatNumber(-12345.12, , TriState.True, TriState.False)	(12345.12)

This example uses the following code to display these examples in a TextBox.

Private Sub Form1_Load(ByVal sender As System.Object, ByVal _
    e As System.EventArgs) Handles MyBase.Load
    Dim txt As String
    Dim x As Single

    x = 1.23456
    txt &= "FormatNumber(" & x.ToString() & ", 2) = " & _
        FormatNumber(x, 2) & vbCrLf

    x = 0.123456
    txt &= "FormatNumber(" & x.ToString() & ", 2, " & _
        "TriState.False) = " & FormatNumber(x, 2, _
        TriState.False) & vbCrLf
    txt &= "FormatNumber(" & x.ToString() & ", 2, " & _
        "TriState.True) = " & FormatNumber(x, 2, _
        TriState.True) & vbCrLf

    x = -12345.12345
    txt &= "FormatNumber(" & x.ToString() & ", , " & _
        "TriState.False) = " & FormatNumber(x, 2, , _
        TriState.False) & vbCrLf
    txt &= "FormatNumber(" & x.ToString() & ", , " & _
        "TriState.True) = " & FormatNumber(x, 2, , _
        TriState.True) & vbCrLf
    txt &= "FormatNumber(" & x.ToString() & ", , " & _
        "TriState.True, TriState.False) = " & _
        FormatNumber(x, 2, , TriState.True, TriState.False) _
        & vbCrLf

    txtResult.Text = txt
    txtResult.Select(0, 0)
End Sub