# `Real128` Data Type

Holds signed 128-bit (16-byte) IEEE floating-point values in the range −1.189731495357231765085759326628007E+4932 to −3.362103143112093506262677817321753E−4932 for negative values and 3.362103143112093506262677817321753E−4932 to 1.189731495357231765085759326628007E+4932 for positive values.

## Instructions

The data type `Real128` gives the largest and smallest possible magnitudes for a number. `Real128` is two times the size of `Real64` and four times the size of `Real32`.

Precision
Floating-point data types cannot store all values accurately. Some operations can cause results that you think are incorrect. A typical example is when you compare values. See Data Type Troubleshooting for more information.
Default value
When you declare a variable of type `Real128` and do not initialize it, its default value is zero (0.0).
Zeros at the end
The floating-point data types usually cannot show 0 characters at the end, after the decimal point. Thus numbers, for example, 1.4200 and 1.42 are the same value. If you must show zeros at the end, you must use a formatter procedure.
Type characters
`Real128` has no type characters.

## Shared methods and properties

``Real128.Default As Real128``
Returns the default value, `0.0`.
``Real128.Epsilon As Real128``
Returns the smallest difference between two values.
``Real128.IsInf(num As Real128) As Boolean``
Returns true if `num` is infinity (positive or negative). Mathematical overflow is one cause of this result.
``Real128.IsNaN(num As Real128) As Boolean``
Returns true if `num` is not a number (NaN). “Zero divided by zero” and “square root of a negative” are two causes of this result.
``Real128.IsNegInf(num As Real128) As Boolean``
Returns true if `num` is negative infinity.
``Real128.IsPosInf(num As Real128) As Boolean``
Returns true if `num` is positive infinity.
``Real128.Max As Real128``
Returns the maximum positive value.
``Real128.Min As Real128``
Returns the minimum negative value.
``Real128.Parse(str As String, Optional #format As Format) As Real128``
Tries to parse a string that shows as a floating-point number.
If `#format` is not given or is `#Null`, it uses the format of the local culture. Or you can make it clear with `Format.UserLocale`.
If `#format` is `Format.RealLiteral`, it uses the format of a literal of type `Real128`.
``Real128.Size As Int32``
Returns the number of available bytes. This is always 16.

## Examples

``````Dim foo As Real128
``````