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Long data type (Visual Basic)

  • Άρθρο

Holds signed 64-bit (8-byte) integers ranging in value from -9,223,372,036,854,775,808 through 9,223,372,036,854,775,807 (9.2...E+18).

Remarks

Use the Long data type to contain integer numbers that are too large to fit in the Integer data type.

The default value of Long is 0.

Literal assignments

You can declare and initialize a Long variable by assigning it a decimal literal, a hexadecimal literal, an octal literal, or (starting with Visual Basic 2017) a binary literal. If the integer literal is outside the range of Long (that is, if it is less than Int64.MinValue or greater than Int64.MaxValue, a compilation error occurs.

In the following example, integers equal to 4,294,967,296 that are represented as decimal, hexadecimal, and binary literals are assigned to Long values.

Dim longValue1 As Long = 4294967296
Console.WriteLine(longValue1)

Dim longValue2 As Long = &H100000000
Console.WriteLine(longValue2)

Dim longValue3 As Long = &B1_0000_0000_0000_0000_0000_0000_0000_0000
Console.WriteLine(longValue3)
' The example displays the following output:
'          4294967296
'          4294967296
'          4294967296

Note

You use the prefix &h or &H to denote a hexadecimal literal, the prefix &b or &B to denote a binary literal, and the prefix &o or &O to denote an octal literal. Decimal literals have no prefix.

Starting with Visual Basic 2017, you can also use the underscore character, _, as a digit separator to enhance readability, as the following example shows.

Dim longValue1 As Long = 4_294_967_296
Console.WriteLine(longValue1)

Dim longValue2 As Long = &H1_0000_0000
Console.WriteLine(longValue2)

Dim longValue3 As Long = &B1_0000_0000_0000_0000_0000_0000_0000_0000
Console.WriteLine(longValue3)
' The example displays the following output:
'          4294967296
'          4294967296
'          4294967296

Starting with Visual Basic 15.5, you can also use the underscore character (_) as a leading separator between the prefix and the hexadecimal, binary, or octal digits. For example:

Dim number As Long = &H_0FAC_0326_1489_D68C

To use the underscore character as a leading separator, you must add the following element to your Visual Basic project (*.vbproj) file:

<PropertyGroup>
  <LangVersion>15.5</LangVersion>
</PropertyGroup>

For more information see Select the Visual Basic language version.

Numeric literals can also include the L type character to denote the Long data type, as the following example shows.

Dim number = &H_0FAC_0326_1489_D68CL

Programming tips

  • Interop Considerations. If you are interfacing with components not written for the .NET Framework, for example Automation or COM objects, remember that Long has a different data width (32 bits) in other environments. If you are passing a 32-bit argument to such a component, declare it as Integer instead of Long in your new Visual Basic code.

  • Widening. The Long data type widens to Decimal, Single, or Double. This means you can convert Long to any one of these types without encountering a System.OverflowException error.

  • Type Characters. Appending the literal type character L to a literal forces it to the Long data type. Appending the identifier type character & to any identifier forces it to Long.

  • Framework Type. The corresponding type in the .NET Framework is the System.Int64 structure.

See also