Thread: Simple casting problem

  1. #1
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    Simple casting problem

    I bet this question has come up more then once, I searched but I didn't find any thing that worked?

    how to convert an int to a char[]

    Code:
    int a = 10;
    char buf[100];
    
    buf = (char)a; // wont work...
    
    
    char *buf2;
    
    buf2 = (char *)a; // wont work either
    so how do I do it?

  2. #2
    lfs addicted
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  3. #3
    C++まいる!Cをこわせ!
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    There's also itoa.

  4. #4
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    thanks, sprintf works, didn't get itoa to work.

  5. #5
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    Code:
    int my_num = 1000;
    char my_buf[10];
    _itoa(my_num, my_buf, 10);
    Or
    Code:
    _itoa_s(my_num, my_buf, 10, 10);

  6. #6
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    Quote Originally Posted by micke_b View Post
    didn't get itoa to work.
    That's good. Use sprintf() if want to write portable code. itoa() may work in some C compilers, but sprintf() will work in any C compiler.

  7. #7
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    I doubt very much that micke_b will have either of _itoa or _itoa_s since both are MS special naming (the latter only in the latest two or so versions of VS C++).

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  8. #8
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    That's weird, because the doc says
    Use the ISO C++ conformant _itoa or security-enhanced _itoa_s instead
    So either something is wrong or it's lying.

  9. #9
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    Well, I haven't been able to find a non-Windows version in my 30 seconds or so of googling.

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  10. #10
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    Code:
    int my_num = 1000;
    char my_buf[10];
    _itoa(my_num, my_buf, 10);
    gives: undefined reference to `_itoa'

    Code:
    _itoa_s(my_num, my_buf, 10, 10);
    gives: undefined reference to `_itoa_s'


    no man pages for either.

    running gcc 4.2.1

  11. #11
    C++まいる!Cをこわせ!
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    If you want to give it a try, it's included in <stdlib.h> according to doc. It works on VC++, but I dunno about GCC.
    As as stated, I don't know if it works on non-windows.

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    Had stdlib.h included... so I guess I just use sprintf

  13. #13
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    Sure, there's no real advantage on using itoa anyway.

  14. #14
    lfs addicted
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    maybe interesting: (from "K&R C" )
    Code:
    void reverse(char s[])
    {
            int c,i, j;
            for (i=0,j= strlen(s)-1; i<j ;i++,j--){
                    c= s[i];
                    s[i]=s[j];
                    s[j]=c;
            }
    }
    
    void itoa(int n, char s[])
    {
            int i, sign;
            if ((sign=n)<0)
                    n=-n;
            i=0;
            do {
                    s[i++]= n &#37;     10 +'0';
            }while((n/=10)>0);
            if(sign<0)
                    s[i++]='-';
            s[i]='\0';
            reverse(s);
    }

  15. #15
    Officially An Architect brewbuck's Avatar
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    Quote Originally Posted by Elysia View Post
    That's weird, because the doc says
    So either something is wrong or it's lying.
    Microsoft's documentation is riddled with lies. Most are accidental, some seem pretty damn intentional sometimes.

    I have no idea if itoa() is a standard function in C++. I didn't think it was. At any rate, this is C, not C++.

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