Format Specifier In C++

Question

0.00/5 (No votes)

See more:

Hello All, I'm posting this question after searching Google, but didn't quite understand. In the following code

C++

CString str1;
str1.Format(_T("%%02d°%%02d'%%1.%dlf\""), val)
//val is an integer

This displays decimal degrees, minutes and seconds. But in the seconds part why is it 1.%dlf, why is the decimal, long n float used and also from my understanding %% means print the percentage but the % symbol is not displayed in my interface.

Posted 8-May-12 3:01am

Sumal.V

Updated 8-May-12 4:07am

Add a Solution

Comments

CPallini 8-May-12 9:24am

It looks just a WRONG format specifier. Do you get the right output?

1 solution

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)

Code-o-mat · Accepted Answer · 2012-05-08T03:19:00

Solution 1

I believe what you pasted there will simply generate a format string (btw it is missing an "integer" parameter)

str1.Format(_T("%%02d°%%02d'%%1.%dlf\""), 5);

will give you:
%02d°%02d'%1.5lf"

I supose this is done so the number of decimals can be dynamically modified (in the example the parameter 5 can be varied). After that string has been created, it is probably used to format the actual string.

E.g:
str2.Format(str1, 1,2,3.45678910);

which will result in something like:
01°02'3.45679"

Posted 8-May-12 3:19am

Code-o-mat

Comments

CPallini 8-May-12 9:51am

Wow, I didn't realize that. 5++.

Code-o-mat 8-May-12 10:10am

Thanks. :)

Sumal.V 8-May-12 10:09am

Oops Sorry yes, I have missed the int variable. Have added that now.
But y not just write :

str1.Format(_T("%%02d°%%02d'%%1.%d\""), 5);

In the seconds part, why is lf required?

Code-o-mat 8-May-12 10:20am

That stands for "long double", check here: http://msdn.microsoft.com/en-us/library/tcxf1dw6%28v=vs.80%29.aspx

Sumal.V 8-May-12 10:21am

So why combine int with long double?

Code-o-mat 8-May-12 10:28am

You misunderstand. This:
str1.Format("%%1.%dlf", 5);
will give you:
"%1.5lf"
In this context the "lf" after the %d isn't parsed, it's simply output to the generated string as normal text.

Sumal.V 8-May-12 10:31am

Oh well I get that now.
Thanks :)

Code-o-mat 8-May-12 10:35am

Yourwelcome.