# Double Data Type

Holds signed 64-bit (8-byte) IEEE floating-point values in the range −1.79769313486231570E+308 to −4.94065645841246544E−324 for negative values and 4.94065645841246544E−324 to 1.79769313486231570E+308 for positive values.

## Remarks

Double is short for "double-precision floating-point".

- Precision
- Be aware that floating-point data types are incapable of representing many values exactly. Operations such as comparisons can produce unexpected results. See Troubleshooting Data Types for details.
- Space efficiency
- You can use Double in situations where the greater precision of Quad is unnecessary. In some cases, the ViviFire runtime may be able to pack your data more efficiently and reduce memory consumption.
- Default value
- When you declare a variable of type Double and leave it uninitialized,, its value defaults to zero (0.0).
- Coercion
- Double widens to Real or Quad without any risk of overflow.
- Trailing zeros
- The floating-point data types have no internal means of representing trailing 0 characters following the decimal point. This means that numbers such as 1.4200 and 1.42 represent the same value. If you must display trailing zeros, the number will need to be formatted.
- Type characters
- Double has no type character.

## Examples

```
Dim foo As Double
```