writing strings chars from ints

This is a discussion on writing strings chars from ints within the C++ Programming forums, part of the General Programming Boards category; hey all, trying to do the following: Write a string that has a row of characters, but these characters are ...

  1. #1
    Registered User deleeuw's Avatar
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    writing strings chars from ints

    hey all,
    trying to do the following:
    Write a string that has a row of characters, but these characters are supposed to from integers (but must be written as characters), and I get the following error:

    invalid operands `const char *' and `const char[2]' to binary `operator +'

    I also get (on a different line):

    passing `char' to argument 1 of `fputs(const char *, FILE *)' lacks a cast.

    I presume these two errors are related (and I get get the syntax for casting from the faq), but I'm lost as to the first error.

    THX
    Deum solum fidentia est

  2. #2
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    Code plz.
    Well, there are a few things wrong with your code:

    1) It does not work.
    2) It does not work.
    3) It does not work.

    Hope this helps.

  3. #3
    Registered User deleeuw's Avatar
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    oops, forgot to add it:

    FILE *ci;
    ci=fopen("c:\\vgastrat\\TESTcws.ini", "w");
    int cc=rand()%40;
    char ccq;
    ccq= int (cc);
    int u=rand()%500;
    int e=rand()%4;
    int s=rand()%9;
    char uq= int (u);
    char eq= int (e);
    char sq= int (s);
    fputs(ccq+","+uq+","+eq+","+sq, ci); // error occurs here


    Hope that's not too cryptic
    Deum solum fidentia est

  4. #4
    Just because ygfperson's Avatar
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    You can't add strings like that, not char* strings. Use strcat instead.

  5. #5
    mustang benny bennyandthejets's Avatar
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    Use code tags.
    benforbes@optusnet.com.au
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  6. #6
    Registered User deleeuw's Avatar
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    FILE *ci;

    ci=fopen("c:\\vgastrat\\TESTcws.ini", "w");

    int cc=rand()%40;

    char ccq;
    ccq= int (cc);

    int u=rand()%500;
    int e=rand()%4;
    int s=rand()%9;

    char uq= int (u);
    char eq= int (e);
    char sq= int (s);

    fputs(ccq+","+uq+","+eq+","+sq, ci); // error occurs here



    Hope this is more acceptable
    Deum solum fidentia est

  7. #7
    mustang benny bennyandthejets's Avatar
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    No, sorry, that's still not doing it for me. Actually READ the code tags link I sent you, then you'll see what I mean.
    benforbes@optusnet.com.au
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  8. #8
    Registered User deleeuw's Avatar
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    Code:
         FILE *ci;
    
         ci=fopen("c:\\vgastrat\\TESTcws.ini", "w");
    
         int cc=rand()%40;
    
         char ccq;
         ccq= int (cc);
    
         int u=rand()%500;
         int e=rand()%4;
         int s=rand()%9;
    
        char uq= int (u);
        char eq= int (e);
        char sq= int (s);
    
        fputs(ccq+","+uq+","+eq+","+sq, ci); // error occurs here
    Sorry all (especially bennyandthejets], I'm just not with it tonight.
    Deum solum fidentia est

  9. #9
    mustang benny bennyandthejets's Avatar
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    No problem. As for the problem, I don't understand what the function int() is. Is that even a legal function name?
    benforbes@optusnet.com.au
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  10. #10
    Registered User deleeuw's Avatar
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    Code:
        char uq= int (u);
        char eq= int (e);
        char sq= int (s);
    Ok, my amateurness is showing through:
    I thought that is how one can type cast from int to char.
    Deum solum fidentia est

  11. #11
    mustang benny bennyandthejets's Avatar
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    You would do that like this:

    Code:
    char *uq=new char[8];
    itoa(u,uq,10);
    delete [] uq;
    The first line creates a pointer to a char, then makes it point to an 8 byte memory block.
    The second line converts u to a string and stores it in uq, using the base 10 number system (decimal ).
    The third line deallocates the memory block so that you don't get memory leaks. Only delete [] after you finish with the string.

    Those three lines you wrote should flag a compiler error I'm pretty sure.
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  12. #12
    Registered User newbie_grg's Avatar
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    not necessarily dude!


    >Ok, my amateurness is showing >through:
    >I thought that is how one can type >cast from int to char.
    ummm...

    >You would do that like this:

    >code:
    >char *uq=new char[8];
    >itoa(u,uq,10);
    >delete [] uq;
    It is not necessary to carry out C-ish style in C++...unless one is destined to do so.

    Code:
    #include <iostream>
    using namespace std;
    int main(std::string argc , int argv) {
    int u = 90;
    char uq= (int) u; // you were doing fine 
    cout << uq;         //deeluw. prints 'z'
    system("pause");
    return 0;
    }
    "If knowledge can create problems, it is not through ignorance that we can solve them. "
    -Isaac Asimov(1920-1992)

  13. #13
    mustang benny bennyandthejets's Avatar
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    But doesn't deleeuw want to convert the integer to a string? Ie, if int i=50, he/she wants the string to be "50". That's what my code does.
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  14. #14
    Cat
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    Originally posted by bennyandthejets
    No problem. As for the problem, I don't understand what the function int() is. Is that even a legal function name?
    i = int(c); is the exact same as i = (int) c;. It's a cast.

    Of course, it's not what he wants to do, but it's legal nonetheless.

  15. #15
    Veni Vidi Vice
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    But doesn't deleeuw want to convert the integer to a string? Ie, if int i=50, he/she wants the string to be "50". That's what my code does.
    The C way

    The C++ way
    01000111011011110110111101100100 011101000110100001101001011011100110011101110011 01100100011011110110111001110100 01100011011011110110110101100101 01100101011000010111100101110011 0110100101101110 01101100011010010110011001100101
    Good things donīt come easy in life!!!

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