_Tstof issue with decimal change in region and language

Question

0.00/5 (No votes)

See more:

hi all i have issue with _tstof when we change Decimal in Region and language from . to ,

Basically i have CString of data i have to seprate the comma and i have to take double value form the string.

it working when the Decimal in Region and language is in . but its nt wrking when it changes to ,

Could you please help me regarding the same.

What I have tried:

nData= (1 + str.Find(_T(","), nData+ 1 - 1));
_tstof(CString(str).Mid(nData+ 1 - 1)))

Posted 17-Oct-17 3:13am

Member 12677926

Updated 17-Oct-17 3:44am

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Jochen Arndt · Answer 1 · 2017-10-17T03:44:00

Solution 2

The C library uses it's own localisation settings and is always initially the generic "C" setting. To apply the same settings as for the current Windows user, call

C++

setlocale(LC_ALL, "");

at program start (e.g. in InitInstance for Windows applications or on top of main for command line applications; requires inluding of locale.h).

To set the locale for the C++ library, include locale (without .h) and call

C++

std::locale::global(std::locale(""));

That will also set the locale for the C library.

Note also that the CString class uses the C library to format strings. So the decimal point set by the above calls is also used when passing floating point numbers to CString::[Append]Format().

Posted 17-Oct-17 3:44am

Jochen Arndt

Comments

Member 12677926 17-Oct-17 10:17am

setting to locale cause any problem ?

Jochen Arndt 17-Oct-17 10:27am

No, it is common to do that.

But you must know what it does. If you need for example to read and parse data from a file that uses the dot as decimal point you have to change the locale again for this task (or write a function that replaces the deciaml point character).

Member 12677926 17-Oct-17 10:35am

::_tsetlocale(LC_NUMERIC, _T("C")); i had kept it is wrking

Jochen Arndt 17-Oct-17 11:19am

That will select the dot as decimal point and is the default at program start.

When using atof (and strtod) you just have to ensure that the locale matches the decimal piunt used in the string.

Member 12677926 17-Oct-17 10:35am

is it ok ?

KarstenK · Answer 2 · 2017-10-17T03:41:00

Converting decimals is more tricky than a lot of people think, because there are local settings. Sometimes the "." and sometimes the "," stands for the decimal delimiter. The software must respect that setting. Normally is the setting used, when the program starts.

Read the documentation of _tstof to understand the behavior better. At the end is some sample code which demonstrates the explicit use of some locale settings.

Think about some input validation, for instance changing the "," to "." in the inputted string, or complaining a message that the data format is invalid. This is typical "UI behind" code...

_Tstof issue with decimal change in region and language

2 solutions

Solution 2

Solution 1

Add your solution here

Preview 0

Existing Members

...or Join us