awjackin35
asked on
What is this "%" doing in this code and what is it called and used for in C++?
#include <stdio.h>
3:
4: main()
5: {
6: char c, *ptr_c;
7: int x, *ptr_x;
8: float y, *ptr_y;
9:
10: c = 'A';
11: x = 7;
12: y = 123.45;
13: printf("c: address=%p, content=%c\n", &c, c);
14: printf("x: address=%p, content=%d\n", &x, x);
15: printf("y: address=%p, content=%5.2f\n", &y, y);
16: ptr_c = &c;
3:
4: main()
5: {
6: char c, *ptr_c;
7: int x, *ptr_x;
8: float y, *ptr_y;
9:
10: c = 'A';
11: x = 7;
12: y = 123.45;
13: printf("c: address=%p, content=%c\n", &c, c);
14: printf("x: address=%p, content=%d\n", &x, x);
15: printf("y: address=%p, content=%5.2f\n", &y, y);
16: ptr_c = &c;
Sorry, there's more. The %5.2f means show 5 characters with 2 decimal places, and the %p means address.
ASKER CERTIFIED SOLUTION
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ASKER
So where can I find th format specifiers? Are they in the header file?
See following link:
http://msdn.microsoft.com/library/wcedoc/wcecrt/crt2_89.htm
http://msdn.microsoft.com/library/wcedoc/wcecrt/crt2_89.htm
It is standatd format specification for the pronting out the variables of various types in various form. This used in printf(), sprintf() C-functions.
In the first line, f.e.
printf("c: address=%p, content=%c\n", &c, c);
instead of %p will be printed the address of c variable,
instead of %c - its value.
So, %p means the address formar type, %c - the cahracter format type.
%d means the decimal integer number format,
%f is the floating point number format. %5.2f in your
code means that it will print the floating variable y, resting only first 2 digits after the point and the total width (number of digits, including the point) of your number is 5.
For more information see the microsoft site below.
http://msdn.microsoft.com/library/wcedoc/wcecrt/crt2_89.htm
In the first line, f.e.
printf("c: address=%p, content=%c\n", &c, c);
instead of %p will be printed the address of c variable,
instead of %c - its value.
So, %p means the address formar type, %c - the cahracter format type.
%d means the decimal integer number format,
%f is the floating point number format. %5.2f in your
code means that it will print the floating variable y, resting only first 2 digits after the point and the total width (number of digits, including the point) of your number is 5.
For more information see the microsoft site below.
http://msdn.microsoft.com/library/wcedoc/wcecrt/crt2_89.htm
It called a modular. it is used in this case as a pointer reference. it formats the value to be out putted.
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All of the experts here, for the most part have learn from other experts as to the proper etiquette for posting answer.
An answer should not be posted as an answer, if other experts have previously posted possible answers as comments, and/or have already made contributions to the question.
There are many experts who never post answers as answer. Instead, they post their answers as comments.
If you read the following link, you'll see why this is the preferred method for many of our valued experts, including myself.
https://www.experts-exchange.com/jsp/cmtyQuestAnswer.jsp
Hi (awjackin35):
Feel free to click the [Reject Answer] button near (Answer-poster's) response, even if it seems like a good answer.
Doing so will increase your chance of obtaining additional input from other experts. Later, you can click the [Select Comment as Answer] button on any response.
hakob,
It is agaisnt EE policy to post an answer using a previous experts comments.
In the future, post answer as comment.
It is agaisnt EE policy to post an answer using a previous experts comments.
In the future, post answer as comment.
ASKER
The answer was acceptable but I have to follow the rules.
ASKER
HI mnashadka
Your answer was ver informative to me and thanks!!!!!!!
Mr. Hakob
Your answer was very good as well but I made the same mistake on the Vb forum and so since they are very critical of the protocal on the forums I have to follow the rules.
Your answer was ver informative to me and thanks!!!!!!!
Mr. Hakob
Your answer was very good as well but I made the same mistake on the Vb forum and so since they are very critical of the protocal on the forums I have to follow the rules.
%c means character
%d means digit (integer)
%f means floating point.