new c programmer have problem with pointer....

This is a discussion on new c programmer have problem with pointer.... within the C Programming forums, part of the General Programming Boards category; http://www.exforsys.com/tutorials/c-...-pointers.html the tutorial above is referred. i follow the instruction in the tutorial, unfortunately, when i try to compile it, ...

  1. #1
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    new c programmer have problem with pointer....

    http://www.exforsys.com/tutorials/c-...-pointers.html

    the tutorial above is referred.

    i follow the instruction in the tutorial, unfortunately, when i try to compile it, some error was occurred...

    Code:
    main()
    {
    int *ptr;
    int sum;
    sum=45;
    ptr=?
    printf (“\n Sum is %d\n”, sum);
    printf (“\n The sum pointer is %d”, ptr);
    }
    and this is the error...

    Code:
    Compiler: Default compiler
    Executing  g++.exe...
    g++.exe "D:\C\pointer\04.cpp" -o "D:\C\pointer\04.exe"    -I"d:\Dev-Cpp\lib\gcc\mingw32\3.4.2\include"  -I"d:\Dev-Cpp\include\c++\3.4.2\backward"  -I"d:\Dev-Cpp\include\c++\3.4.2\mingw32"  -I"d:\Dev-Cpp\include\c++\3.4.2"  -I"d:\Dev-Cpp\include"   -L"d:\Dev-Cpp\lib" 
    Executing  g++.exe...
    g++.exe "D:\C\pointer\04.cpp" -o "D:\C\pointer\04.exe"    -I"d:\Dev-Cpp\lib\gcc\mingw32\3.4.2\include"  -I"d:\Dev-Cpp\include\c++\3.4.2\backward"  -I"d:\Dev-Cpp\include\c++\3.4.2\mingw32"  -I"d:\Dev-Cpp\include\c++\3.4.2"  -I"d:\Dev-Cpp\include"   -L"d:\Dev-Cpp\lib" 
    D:\C\pointer\04.cpp: In function `int main()':
    
    D:\C\pointer\04.cpp:6: error: expected primary-expression before '?' token
    D:\C\pointer\04.cpp:7: error: stray '\147' in program
    D:\C\pointer\04.cpp:7: error: stray '\' in program
    D:\C\pointer\04.cpp:7: error: `n' undeclared (first use this function)
    D:\C\pointer\04.cpp:7: error: (Each undeclared identifier is reported only once for each function it appears in.)
    D:\C\pointer\04.cpp:7: error: stray '\' in program
    D:\C\pointer\04.cpp:7: error: stray '\148' in program
    D:\C\pointer\04.cpp:7: error: `printf' undeclared (first use this function)
    D:\C\pointer\04.cpp:7: error: expected `:' before ';' token
    D:\C\pointer\04.cpp:7: error: expected primary-expression before ';' token
    D:\C\pointer\04.cpp:8: error: stray '\147' in program
    D:\C\pointer\04.cpp:8: error: stray '\' in program
    D:\C\pointer\04.cpp:8: error: stray '\148' in program
    
    Execution terminated
    mmm...what was happened..i followed exactly the tutorial, but still have some error...

  2. #2
    CSharpener vart's Avatar
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    ptr should be set to point to sum
    ptr=? has no meaning
    I think tutorial wants you to figure out what should be put in place of ?

    %d is for integers %p for pointers
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

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    oic, thank you for ur prompt reply, really appreciate it
    so i just modified it...and this time there is no error...but i'm not sure whether it is correct or not....

    Code:
    #include<stdio.h>
    
    main()
    {
      int *ptr;
      int sum;
      sum=45;
      ptr=&sum;
      printf ("Sum is %d\n", sum);
      printf ("The sum pointer is %d\n",ptr);
    }
    output

    Code:
    Sum is 45
    The sum pointer is 2293616

  4. #4
    CSharpener vart's Avatar
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    main should be declared as int
    int main()

    and correct way to print the pointer is using &#37;p format
    the rest seems to be ok
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  5. #5
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    Code:
    #include<stdio.h>
    
    int main()
    {
      int *ptr;
      int sum;
      sum=45;
      ptr=&sum;
      printf ("Sum is %d\n", sum);
      printf ("The sum pointer is %p\n",ptr);
      printf ("The sum is %d\n",*ptr);
      return 0;
    }

  6. #6
    Registered User ssharish2005's Avatar
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    Here is better tutorial than that Pointers. I see some bugs on your tutorial.

    ssharish

  7. #7
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    Quote Originally Posted by ssharish2005 View Post
    Here is better tutorial than that Pointers. I see some bugs on your tutorial.

    ssharish
    I am also learning C, and I can tell you from experience it is damn hard to find a decent tuturial that doesn't assume to much, explain too little, or have outright errors. Same problem with VB tutorials I've used.

    It seems that you have to combine like 5 different tutorials just to get a decent grasp of what's going on overall.

    I'm told that Programming in C by Stephen Koch is suppose to be an incredible, all around easy to understand book on the subject. However, I have not yet bought a copy so I don't know whether it is or isn't for myself.

  8. #8
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    Quote Originally Posted by A34Chris View Post
    I am also learning C, and I can tell you from experience it is damn hard to find a decent tuturial that doesn't assume to much, explain too little, or have outright errors. Same problem with VB tutorials I've used.
    That's probably because it's darn hard to WRITE the tutorials in such a way that you explain the right amount. If you have too much explanation, people will go elsewhere to find the solution. If you don't explain enough, the same problem - but slightly less amount of work.

    The other problem is of course that if you write tutorials, you'd better know the subject quite well, which may also mean that you take things for granted.

    Outright errors should be reported to the author / webmaster of the site posting such code.

    --
    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  9. #9
    Registered User ssharish2005's Avatar
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    I am also learning C, and I can tell you from experience it is damn hard to find a decent tuturial that doesn't assume to much, explain too little, or have outright errors. Same problem with VB tutorials I've used.
    The reason I gave him a better link is because the old link which he was refereeing wasn't the start link for pointer. It confuses any beginner es. Even some of the example code dosn;t work in that page. Which is like no point looking into that site anymore.

    Pointer are not those topic that would be understandable at a glance, you should got thought it twice or more to clearly understand whats going on behind the senses.

    ssharish

  10. #10
    Woof, woof! zacs7's Avatar
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    And the best way to solve the tutorial problem is...?
    Get a good book, from a good publisher, K&R for example.

    As matsp said, the hard part about writing tutorials is you have to know your stuff damn well but you equally have to know how to explain what you know (on a begginers level) AND why it is so, also how to build-up rather than jumping straight into the deep-end.

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