Counting number of strings in an array

This is a discussion on Counting number of strings in an array within the C Programming forums, part of the General Programming Boards category; Hey there! I have an array of strings where I declare all strings like this: Code: string[2] = "\xFB\x9D"; to ...

  1. #1
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    Counting number of strings in an array

    Hey there!

    I have an array of strings where I declare all strings like this:
    Code:
    string[2] = "\xFB\x9D";
    to represent 2 chars in one variable. All tend to be only 2 bytes long.

    Code:
    char a[2] = "\xFB\x01";
    char b[2] = "\xFF\x01";
    char c[2] = "\xD1\xF5";
    ...
    
    char *pitems[] = {a, c, f, z};
    What would be the safest&easiest way to count the number of strings in this array? Because they are not \0-terminated I can't use strlen().

    Thanks in advance,
    Hawk

  2. #2
    and the Hat of Guessing tabstop's Avatar
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    If you do not pass the array to a function, but are in the block where it is defined:
    Code:
    sizeof(pitems)/sizeof(pitems[0])
    If you do pass the array to a function, you're just out of luck.

  3. #3
    Algorithm Dissector iMalc's Avatar
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    Well actually this
    Code:
    char *pitems[] = {a, c, f, z};
    is declaring an array of char pointers, so you can easily add a NULL pointer at the end and use that to know hoiw many of them there are in any function this is passed to. E.g:
    Code:
    char *pitems[] = {a, c, f, z, NULL};
    foo(pItems);
    
    //...
    
    void foo(char** pItem)
    {
        while (pItem != NULL)
        {
            bar(*pItem);
        }
    }
    Last edited by laserlight; 10-24-2009 at 04:35 AM. Reason: Closed code tag.
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  4. #4
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    Thank you for the input. I (finally) added both methods to my program to find them if I need them in another program also. Yet I don't know why sizeof(pitems)/sizeof(pitems[0]) wouldn't work if I passed the array to another function.

  5. #5
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    Since arrays sizes degrade to pointers when they're passed to a function, the sizeof(arrayName) becomes just the size of the pointer to that data type (int, char, whatever).

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