INFO: The Difference Among Visual FoxPro Numeric Data Types (129171)


The information in this article applies to:

  • Microsoft Visual FoxPro for Windows 3.0
  • Microsoft Visual FoxPro for Windows 5.0
  • Microsoft Visual FoxPro for Windows 6.0
This article was previously published under Q129171

SUMMARY

With the addition of Double, Integer, and Currency data types, Visual FoxPro version 3.0 now has five numeric data type possibilities. This article describes the difference among the five numeric data types, explaining the circumstances under which each should be used.

MORE INFORMATION

Currency

The Currency data type is new to Visual FoxPro version 3.0. Use it to store monetary amounts. Currency requires 8 bytes in memory and 8 bytes on disk.

With the Currency data type, data is limited to 4 decimal positions of precision. The numeric precision of Currency fields is: 
   -92233720368477.5807 to 922337203685477.5807

Double

The Double data type is new to Visual FoxPro version 3.0. The double is a floating point numeric stored to disk as an 8-byte binary value. Use the double data type when the numeric precision of numeric, float, or integer fields is insufficient. The numeric precision of double fields is: 
   -4.94065648541247E-324 to 1.79769313486232E+308

Integer

The Integer data type is new to Visual FoxPro. Use the integer data type to store integers (numeric values without decimal positions). Integers require 4 bytes on disk and in memory. The numeric precision of integer fields is: 
   -2147483647 to 2147483646

Numeric and Float

The numeric and float data types each existed in FoxPro versions 2.5 and 2.6. In Visual FoxPro, the two data types are identical (float is provided for compatibility reasons only). Use them to store integers or numbers with decimal positions. Numeric and float data types are stored in memory as 6 bytes and are stored on disk from between 1 and 20 bytes. They are stored in a table on disk. The numeric precision of numeric and float fields is: 
   .9999999999E+20 to - .9999999999E+19
Modification Type:MinorLast Reviewed:3/3/2005
Keywords:kbinfo KB129171
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