Finding the ASCII value of a string?

This is a discussion on Finding the ASCII value of a string? within the C Programming forums, part of the General Programming Boards category; If I define a string as Code: char found[100]; and then proceed to try Code: if ((int) found[7]==80)) { printf ...

  1. #1
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    Finding the ASCII value of a string?

    If I define a string as
    Code:
    char found[100];
    and then proceed to try
    Code:
    if ((int) found[7]==80))
    {
     printf ("%s",found);
    }
    It should only occur if the seventh char in found is P, whose ascii value is 80, correct? Is there an easier way to do this?

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    Code:
    if(found[6] == 'P')
    {
      printf("%s\n", found);
    }
    Since 0 is included you would put [6] not [7] if you want to find the 7th letter

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    Thanks, that fixed the problem. I'm new to strings, so I should've checked that first...

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    Captain Crash brewbuck's Avatar
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    Quote Originally Posted by Nicheter View Post
    It should only occur if the seventh char in found is P, whose ascii value is 80, correct? Is there an easier way to do this?
    The ASCII code for 'P' is 80, but there is no guarantee that the system's character set is actually ASCII. It is better to compare explicitly with 'P' not just for clarity but because you do not necessarily know the character set. This of course assumes that the compiler is using the same character set as the platform, which is usually true.
    Code:
    //try
    //{
    	if (a) do { f( b); } while(1);
    	else   do { f(!b); } while(1);
    //}

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    Ah, well, that's a good tip, thanks. One other question, while I'm on the subject of strings. Is there any way to do multiple string comparisons in a shorter form than, for example,
    Code:
    if((strcmp(str1,"apple")==0)||(strcmp(str1,"bananna")==0)||(strcmp(str1,"fruit")==0)||...
    and so on.

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    You could have an array of strings, e.g.
    Code:
    const char *fruits[]= { "apple", "banana", "pear", ... } ;
    and then loop through that array to see if you find it.

    --
    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.

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    Well you don't need so much "(" and ")"

    Code:
    if(strcmp(str1,"apple")==0 || strcmp(str1,"bananna")==0 || strcmp(str1,"fruit")==0)
    Last edited by 39ster; 07-16-2008 at 10:08 AM. Reason: Added "need"

  8. #8
    CSharpener vart's Avatar
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    Code:
    int bFound = 0;
    bFound = (strcmp(str1,"apple")==0);
    if(!bFound)
        bFound = (strcmp(str1,"bananna")==0);
    if(!bFound)
        bFound = (strcmp(str1,"fruit")==0);
    ...
    for example
    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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    Thanks guys, but Vart, isn't your solution even longer then the initial example?

  10. #10
    CSharpener vart's Avatar
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    Quote Originally Posted by Nicheter View Post
    Thanks guys, but Vart, isn't your solution even longer then the initial example?
    Strings are short - so IMHO code is more readable...
    It takes alittle more lines... so what? Put this code into another function, add loop and array as suggested by matsp... but do not write lines longer than the screen width
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  11. #11
    Frequently Quite Prolix dwks's Avatar
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    matsp's suggestion is probably best, especially if you have over, say, five strings. It's pretty easy to do, too.
    Code:
    /*! Returns true if \a needle is a fruit.
        \param a The string that might represent a fruit.
        \return True (nonzero) if \a needle is a fruit.
    */
    int match(const char *needle) {
        const char *haystack[] = {
            "apple", "banana", "pear", /* ... */
        }
        size_t x;
    
        for(x = 0; x < sizeof(haystack) / sizeof(*haystack); x ++) {
            if(!strcmp(needle, haystack[x])) return 1;
        }
    
        return 0;
    }
    Plus, if you get a lot of strings, you can sort them and use a binary search instead of a linear search quite easily.
    dwk

    Seek and ye shall find. quaere et invenies.

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    Well, thanks! One final, unrelated, question:
    if i use my main statement as
    Code:
    int main(int argc, char *argv[])
    it allows me to take command line arguments, and works fine. But if, using windows, I try to drop a file onto the program so as to make that the second argument, it does not work properly? Well, that is to say, it executes with no errors, but the outputted file is nowhere to be found...

  13. #13
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    Quote Originally Posted by Nicheter View Post
    Well, that is to say, it executes with no errors, but the outputted file is nowhere to be found...
    Nowhere to be found, or "not where you expect it"?

    --
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    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.

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    it outputs a file 'reformatted.txt' and a search of the entirety of the computer turns up nothing. After checking the program's execution one more time, it does seem to be executing properly, just the file isn't appearing where it should/at all? I thought it may have been someplace else, but apparently this is not the case.

  15. #15
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    Quote Originally Posted by Nicheter View Post
    it outputs a file 'reformatted.txt' and a search of the entirety of the computer turns up nothing. After checking the program's execution one more time, it does seem to be executing properly, just the file isn't appearing where it should/at all?
    Can you post the 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.

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