Introduction
Formatting of numeric values with commas looks nice, but sometimes commas are not
the correct thousands separator - many countries use "." for thousands separator.
To ensure the correct separator, the Win32 function GetNumberFormat()
should be used. However, this API requires the setup of a decimal separator, thousands separator,
digit grouping, etc., which can add many lines of code to do a simple thing.
After needing to use GetNumberFormat()
one more time, I decide to
make a simple function with defaults taken from the locale.
XFormatNumber Features
XFormatNumber
takes as input a numeric string, which may or may not contain decimal point
and fractional digits. XFormatNumber
is defined as
CString XFormatNumber(LPCTSTR lpszNumber, int nFracDigits)
The parameter
lpszNumber is numeric string, and the
nFracDigits parameter
specifies whether to include fractional digits in the returned
CString
: 0 means
no fractional digits, >0 means return
nFracDigits
fractional digits, and -1 means
return however many fractional digits are contained in the numeric string.
XFormatNumber Demo
The demo app shows results for various formatting options:
m_List.AddString(XFormatNumber(_T("1"), -1));
m_List.AddString(XFormatNumber(_T("10"), -1));
m_List.AddString(XFormatNumber(_T("100"), -1));
m_List.AddString(XFormatNumber(_T("1000"), -1));
m_List.AddString(XFormatNumber(_T("10000"), -1));
m_List.AddString(XFormatNumber(_T("100000"), -1));
m_List.AddString(XFormatNumber(_T("1000000"), -1));
m_List.AddString(XFormatNumber(_T("10000000"), -1));
m_List.AddString(XFormatNumber(_T("100000000"), -1));
m_List.AddString(XFormatNumber(_T("1000000000"), -1));
m_List.AddString(XFormatNumber(_T("1000.0"), -1));
m_List.AddString(XFormatNumber(_T("1000.00"), -1));
m_List.AddString(XFormatNumber(_T("1000.000"), -1));
m_List.AddString(XFormatNumber(_T("1000.0000"), -1));
m_List.AddString(XFormatNumber(_T("1000.00000"), 1));

Usage
This software is released into the public domain.
You are free to use it in any way you like.
If you modify it or extend it, please to consider
posting new code here for everyone to share.
This software is provided "as is" with no expressed
or implied warranty. I accept no
liability for any damage or loss of business that this
software may cause.