String comparison question

This is a discussion on String comparison question within the C Programming forums, part of the General Programming Boards category; Say I have a char array called dave, with elements dave[0] = 'h' and dave[1] = 'i' What is the ...

  1. #1
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    String comparison question

    Say I have a char array called dave, with elements dave[0] = 'h' and dave[1] = 'i'

    What is the best way of finding out if they char array is equal to 'hi'?

    Is the best way of doing comparing each element at a time such as if(dave[0] == 'h' && dave[1] == 'i') or is there a C function which does this for me?

    Thanks

  2. #2
    Registered User Micko's Avatar
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    Read about function named : strcmp with prototype in string.h!
    Gotta love the "please fix this for me, but I'm not going to tell you which functions we're allowed to use" posts.
    It's like teaching people to walk by first breaking their legs - muppet teachers! - Salem

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    K safe.

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    strcmp will work, provided both strings are exactly that - strings. A string in C is terminated with a zero byte, thus dave[2] would have to be 0. I mention that detail because you don't make it clear in your post as to whether this is indeed the case.

    Failing that, there is memcmp - compare memory for a specified number of bytes.
    I think you can put a signature here.

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    Hang on a minute, I'm comparing it to find out if the string is a certain word, I'm not comparing 2 different strings.

    I only have one string and I want to compare that with a variety of words.

    Is there a function that can help me with this?

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    Could I do...?

    Code:
    strcmp(dave,"hi");

  7. #7
    Code Goddess Prelude's Avatar
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    >I only have one string and I want to compare that with a variety of words.
    You would need to write this manually. Fortunately, it's relatively simple:
    Code:
    char buf[BUFSIZ]; /* Your string */
    
    if ( fgets ( buf, sizeof buf, stdin ) != NULL ) {
      char *words[] = {"This","is","a","test",NULL};
      size_t i;
    
      for ( i = 0; words[i] != NULL; i++ ) {
        if ( strcmp ( buf, words[i] ) == 0 ) {
          /* Matching word */
        }
      }
    }
    My best code is written with the delete key.

  8. #8
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    Quote Originally Posted by Wiretron
    Could I do...?

    Code:
    strcmp(dave,"hi");
    So this wouldn't work?

  9. #9
    ZuK
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    Quote Originally Posted by Wiretron
    Say I have a char array called dave, with elements dave[0] = 'h' and dave[1] = 'i'
    it will only work if dave[2] == '\0'
    Kurt

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