how to insert variables into string with % sign?

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Views: 918 | Replies: 5 | Solved

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Join Date: Jul 2007

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how to insert variables into string with % sign?

Feb 13th, 2008

Hello everyone!
I have seen some code where some variable gets inserted into string throught the % sign, like so -

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("insert into songs values (%Q ,%d, %d, %Q, %Q, %Q, ... ", someInt, someChar, someChar... )

I have tried to look it up in google but I do not know what this is called. What is it and where can I find a reference for it? Thanks!

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Re: how to insert variables into string with % sign?

Feb 13th, 2008

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("insert into songs values (%Q ,%d, %d, %Q, %Q, %Q, ... ", someInt, someChar, someChar... )

Do you use someting like sprintf_s()? (or sprintf())
example:

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char c = 'x';
int i = 123;
char buffer[1024];
sprintf(buffer, "Test number: %d, test char, %c", i,c);
char c = 'x';
int i = 123;
char buffer[1024];
sprintf(buffer, "Test number: %d, test char, %c", i,c);

Last edited by niek_e : Feb 13th, 2008 at 3:48 am.

"= != =="

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Re: how to insert variables into string with % sign?

Feb 13th, 2008

No, but I want to use this for sqlite3 to insert data into tables, like combine the "insert into" command with data. Do I have to "print" it to string and then use it? Thanks

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Re: how to insert variables into string with % sign?

Feb 13th, 2008

> I have seen some code where some variable gets inserted into string through the % sign
the code you saw was probably using the Boost.Format library to insert stuff into a stringstream. http://www.boost.org/libs/format/doc/format.html

Last edited by vijayan121 : Feb 13th, 2008 at 5:36 am.

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Re: how to insert variables into string with % sign?

Feb 13th, 2008

The string with the %x symbols in it are parsed to find each symbol. The letter is then looked at to figure out what field is supposed to go there. Then the string is changed by removing the %x and whatever field is requested replaces it.

Usually the data comes out of variables and/or structures the program has already read or generated.

There is no function to do this if that's what you're looking for. The function is written by the programmers developing the system.

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