Visual Basic supplies several *numeric data types* for handling numbers in various representations. *Integral* types represent only whole numbers (positive, negative, and zero), and *nonintegral* types represent numbers with both integer and fractional parts.

For a table showing a side-by-side comparison of the Visual Basic data types, see Data Types.

## Integral Numeric Types

*Integral data types* are those that represent only numbers without fractional parts.

The *signed* integral data types are SByte Data Type (8-bit), Short Data Type (16-bit), Integer Data Type (32-bit), and Long Data Type (64-bit). If a variable always stores integers rather than fractional numbers, declare it as one of these types.

The *unsigned* integral types are Byte Data Type (8-bit), UShort Data Type (16-bit), UInteger Data Type (32-bit), and ULong Data Type (64-bit). If a variable contains binary data, or data of unknown nature, declare it as one of these types.

### Performance

Arithmetic operations are faster with integral types than with other data types. They are fastest with the `Integer`

and `UInteger`

types in Visual Basic.

### Large Integers

If you need to hold an integer larger than the `Integer`

data type can hold, you can use the `Long`

data type instead. `Long`

variables can hold numbers from -9,223,372,036,854,775,808 through 9,223,372,036,854,775,807. Operations with `Long`

are slightly slower than with `Integer`

.

If you need even larger values, you can use the Decimal Data Type. You can hold numbers from -79,228,162,514,264,337,593,543,950,335 through 79,228,162,514,264,337,593,543,950,335 in a `Decimal`

variable if you do not use any decimal places. However, operations with `Decimal`

numbers are considerably slower than with any other numeric data type.

### Small Integers

If you do not need the full range of the `Integer`

data type, you can use the `Short`

data type, which can hold integers from -32,768 through 32,767. For the smallest integer range, the `SByte`

data type holds integers from -128 through 127. If you have a very large number of variables that hold small integers, the common language runtime can sometimes store your `Short`

and `SByte`

variables more efficiently and save memory consumption. However, operations with `Short`

and `SByte`

are somewhat slower than with `Integer`

.

### Unsigned Integers

If you know that your variable never needs to hold a negative number, you can use the *unsigned types*`Byte`

, `UShort`

, `UInteger`

, and `ULong`

. Each of these data types can hold a positive integer twice as large as its corresponding signed type (`SByte`

, `Short`

, `Integer`

, and `Long`

). In terms of performance, each unsigned type is exactly as efficient as its corresponding signed type. In particular, `UInteger`

shares with `Integer`

the distinction of being the most efficient of all the elementary numeric data types.

## Nonintegral Numeric Types

*Nonintegral data types* are those that represent numbers with both integer and fractional parts.

The nonintegral numeric data types are `Decimal`

(128-bit fixed point), Single Data Type (32-bit floating point), and Double Data Type (64-bit floating point). They are all signed types. If a variable can contain a fraction, declare it as one of these types.

`Decimal`

is not a floating-point data type. `Decimal`

numbers have a binary integer value and an integer scaling factor that specifies what portion of the value is a decimal fraction.

You can use `Decimal`

variables for money values. The advantage is the precision of the values. The `Double`

data type is faster and requires less memory, but it is subject to rounding errors. The `Decimal`

data type retains complete accuracy to 28 decimal places.

Floating-point (`Single`

and `Double`

) numbers have larger ranges than `Decimal`

numbers but can be subject to rounding errors. Floating-point types support fewer significant digits than `Decimal`

but can represent values of greater magnitude.

Nonintegral number values can be expressed as mmmEeee, in which mmm is the *mantissa* (the significant digits) and eee is the *exponent* (a power of 10). The highest positive values of the nonintegral types are 7.9228162514264337593543950335E+28 for `Decimal`

, 3.4028235E+38 for `Single`

, and 1.79769313486231570E+308 for `Double`

.

### Performance

`Double`

is the most efficient of the fractional data types, because the processors on current platforms perform floating-point operations in double precision. However, operations with `Double`

are not as fast as with the integral types such as `Integer`

.

### Small Magnitudes

For numbers with the smallest possible magnitude (closest to 0), `Double`

variables can hold numbers as small as -4.94065645841246544E-324 for negative values and 4.94065645841246544E-324 for positive values.

### Small Fractional Numbers

If you do not need the full range of the `Double`

data type, you can use the `Single`

data type, which can hold floating-point numbers from -3.4028235E+38 through 3.4028235E+38. The smallest magnitudes for `Single`

variables are -1.401298E-45 for negative values and 1.401298E-45 for positive values. If you have a very large number of variables that hold small floating-point numbers, the common language runtime can sometimes store your `Single`

variables more efficiently and save memory consumption.

## See Also

Elementary Data Types

Character Data Types

Miscellaneous Data Types

Troubleshooting Data Types

How to: Call a Windows Function that Takes Unsigned Types