Thread: Address of a C++ reference

  1. 09-26-2011 #1
    juice
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    Address of a C++ reference

    I was told that in c++ the address of a data type and the address of its reference are same. But when I compiled and executed the following code in Microsoft Visual C++ 6.0, it printed two seperate addresses for i and j. Any ideas, why??

    Code:
    #include<iostream.h>
void main()
{
	const int i=10;
	const int &j=i;
	
        cout<<"\nAddress of i="<<&i<<"\nAdress of j="<<&j<<endl;
}
    Last edited by juice; 09-26-2011 at 10:40 AM.
  2. 09-26-2011 #2
    laserlight
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    * Thread moved to C++ programming forum. *

    Quote Originally Posted by juice
    I was told that in c++ the address of a data type and the address of its reference are same. But when I compiled and executed the following code in Microsoft Visual C++ 6.0, it printed two seperate addresses for i and j. Any ideas, why??
    Maybe it is a bug with MSVC6.

    By the way:
    • <iostream.h> should be <iostream>
    • void main should be int main
    • In order to use the names cout and endl without qualifying them, you should use the appropriate using directive (e.g., using namespace std; ) or using declarations (e.g., using std::cout; ).
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way
  3. 09-26-2011 #3
    juice
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    Actually different addresses are reported when the variables are declared 'constant'.
  4. 09-26-2011 #4
    AndrewHunter
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    Quote Originally Posted by juice View Post
    Actually different addresses are reported when the variables are declared 'constant'.
    Probably still a bug; VS 2010 gives the correct answer.
    Quote Originally Posted by anduril462 View Post
    Now, please, for the love of all things good and holy, think about what you're doing! Don't just run around willy-nilly, coding like a drunk two-year-old....
    Quote Originally Posted by quzah View Post
    ..... Just don't be surprised when I say you aren't using standard C anymore, and as such,are off in your own little universe that I will completely disregard.
    Warning: Some or all of my posted code may be non-standard and as such should not be used and in no case looked at.
  5. 09-26-2011 #5
    laserlight
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    Quote Originally Posted by juice
    Actually different addresses are reported when the variables are declared 'constant'.
    That should not make a difference. Since j is an alias of i, the address of j is the address of i.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way
  6. 09-26-2011 #6
    juice
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    Hey, I tried to build it with my MSVC 2010, and it flags an error:
    "Cannot open include file: 'iostream.h': No such file or directory"

    Any ideas why?? I am new to this compiler.
  7. 09-26-2011 #7
    laserlight
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    Quote Originally Posted by juice
    Hey, I tried to build it with my MSVC 2010, and it flags an error:
    "Cannot open include file: 'iostream.h': No such file or directory"

    Any ideas why?? I am new to this compiler.
    Refer to my corrections in post #2.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way
  8. 09-26-2011 #8
    juice
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    Yeah, its a bug in MSVC6.
  9. 09-26-2011 #9
    juice
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    Thanx laserlight.
    Can you explain me why <iostream.h> should be <iostream>..
  10. 09-26-2011 #10
    laserlight
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    Quote Originally Posted by juice
    Can you explain me why <iostream.h> should be <iostream>
    Yes. <iostream> is the correct standard header.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way
  11. 09-26-2011 #11
    Elysia
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    Quote Originally Posted by juice View Post
    Thanx laserlight.
    Can you explain me why <iostream.h> should be <iostream>..
    <iostream.h> is not a standard header, wheras <iostream> is.
    In some long ages past, iostream.h may have been part of C++, but it certainly isn't as of today.

    Also, there is no reference to speak of in this thread. All you are doing is taking the address of a variable, hence creating a pointer. But a pointer is not a reference. Separate the concepts.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.
  12. 09-26-2011 #12
    laserlight
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    Quote Originally Posted by Elysia
    Also, there is no reference to speak of in this thread.
    That is not correct. In the code posted in post #1, j is a reference.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way
  13. 09-27-2011 #13
    Elysia
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    You are right. My bad.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.
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