Redigeeri

Jagamisviis:

Integer data type (Visual Basic)

  • Artikkel

Holds signed 32-bit (4-byte) integers that range in value from -2,147,483,648 through 2,147,483,647.

Remarks

The Integer data type provides optimal performance on a 32-bit processor. The other integral types are slower to load and store from and to memory.

The default value of Integer is 0.

Literal assignments

You can declare and initialize an Integer 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 Integer (that is, if it is less than Int32.MinValue or greater than Int32.MaxValue, a compilation error occurs.

In the following example, integers equal to 90,946 that are represented as decimal, hexadecimal, and binary literals are assigned to Integer values.

Dim intValue1 As Integer = 90946
Console.WriteLine(intValue1)
Dim intValue2 As Integer = &H16342
Console.WriteLine(intValue2)

Dim intValue3 As Integer = &B0001_0110_0011_0100_0010
Console.WriteLine(intValue3)
' The example displays the following output:
'          90946
'          90946
'          90946

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 intValue1 As Integer = 90_946
Console.WriteLine(intValue1)

Dim intValue2 As Integer = &H0001_6342
Console.WriteLine(intValue2)

Dim intValue3 As Integer = &B0001_0110_0011_0100_0010
Console.WriteLine(intValue3)
' The example displays the following output:
'          90946
'          90946
'          90946

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 Integer = &H_C305_F860

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 I type character to denote the Integer data type, as the following example shows.

Dim number = &H_035826I

Programming tips

  • Interop Considerations. If you are interfacing with components not written for the .NET Framework, such as Automation or COM objects, remember that Integer has a different data width (16 bits) in other environments. If you are passing a 16-bit argument to such a component, declare it as Short instead of Integer in your new Visual Basic code.

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

  • Type Characters. Appending the literal type character I to a literal forces it to the Integer data type. Appending the identifier type character % to any identifier forces it to Integer.

  • Framework Type. The corresponding type in the .NET Framework is the System.Int32 structure.

Range

If you try to set a variable of an integral type to a number outside the range for that type, an error occurs. If you try to set it to a fraction, the number is rounded up or down to the nearest integer value. If the number is equally close to two integer values, the value is rounded to the nearest even integer. This behavior minimizes rounding errors that result from consistently rounding a midpoint value in a single direction. The following code shows examples of rounding.

' The valid range of an Integer variable is -2147483648 through +2147483647.  
Dim k As Integer  
' The following statement causes an error because the value is too large.  
k = 2147483648  
' The following statement sets k to 6.  
k = 5.9  
' The following statement sets k to 4  
k = 4.5  
' The following statement sets k to 6  
' Note, Visual Basic uses banker’s rounding (toward nearest even number)  
k = 5.5

See also