array of ints

This is a discussion on array of ints within the C Programming forums, part of the General Programming Boards category; I have these codes: Code: #include <stdio.h> #include <stdlib.h> #include <conio.h> int main() { int arrayofints2[5]; int i; printf("Enter five ...

  1. #1
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    array of ints

    I have these codes:

    Code:
    #include <stdio.h>
    #include <stdlib.h>
    #include <conio.h>
    int main()
    {
      int arrayofints2[5];
      int i;
      
      
      printf("Enter five numbers\t");
      
      for (i=0; i<5; i++){
           scanf("%d", &arrayofints2[i]);
           }
      for (i=0; i<5; i++){
          printf("arrayofints2[%d]has a value of %d\n",i,arrayofints2[i]);
          }
      getch();	
      return 0;
    }
    I don't understand why i have to push enter every time i enter number? When I try to enter numbers horizontally with spaces i've got error message that program performed illegal operation.

    Thanks.

  2. #2
    VOX
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    Others may yell at you, so take out conio.h and replace getch() with getchar(). With scanf you have to press enter after input. That's just the way it is. If you wanted to enter a number with more than one digit that enter would mean the difference between workage and not-workage.

    If you are entering single digit numbers you can use getchar() instead of scanf().
    Last edited by VOX; 12-31-2004 at 06:52 PM.
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  3. #3
    ATH0 quzah's Avatar
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    The real reason is because you're telling scanf to read one at a time.

    Quzah.
    Hope is the first step on the road to disappointment.

  4. #4
    and the hat of wrongness Salem's Avatar
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    > I don't understand why i have to push enter every time i enter number?
    You don't need to - code works fine for me (after removing the DOS-isms)

    Example
    Code:
    $ ./a.out
    Enter five numbers      1 2 3 4 5
    arrayofints2[0]has a value of 1
    arrayofints2[1]has a value of 2
    arrayofints2[2]has a value of 3
    arrayofints2[3]has a value of 4
    arrayofints2[4]has a value of 5
    $ ./a.out
    Enter five numbers      1 2 3
    4 5
    arrayofints2[0]has a value of 1
    arrayofints2[1]has a value of 2
    arrayofints2[2]has a value of 3
    arrayofints2[3]has a value of 4
    arrayofints2[4]has a value of 5
    $ ./a.out
    Enter five numbers      1
    2 3 4
    5
    arrayofints2[0]has a value of 1
    arrayofints2[1]has a value of 2
    arrayofints2[2]has a value of 3
    arrayofints2[3]has a value of 4
    arrayofints2[4]has a value of 5
    Whether they're all on one line or split across several lines should not matter.

    However, your code will break if there is anything other than spaces, newlines or digits.

  5. #5
    Helper
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    Quote Originally Posted by barim
    Code:
    #include <stdio.h>
    #include <stdlib.h>
    #include <conio.h>
    int main()
    {
      int arrayofints2[5];
      int i;
      
      printf("Enter five numbers\t");
      
      for (i=0; i<5; i++){
           scanf("%d", &arrayofints2[i]);
           }
      for (i=0; i<5; i++){
          printf("arrayofints2[%d]has a value of %d\n",i,arrayofints2[i]);
          }
      getch();	
      return 0;
    }
    I don't understand why i have to push enter every time i enter number? When I try to enter numbers horizontally with spaces i've got error message that program performed illegal operation.
    Sounds good to me:
    Code:
    Enter five numbers      1 2 3 4 5
    arrayofints2[0]has a value of 1
    arrayofints2[1]has a value of 2
    arrayofints2[2]has a value of 3
    arrayofints2[3]has a value of 4
    arrayofints2[4]has a value of 5
    That said, I would not have mixed input functions from stdio and conio in the same program. It's an open door to hell...

    Also, the 'prompt' not being terminated by a '\n', I suggest to add a
    Code:
       fflush(stdout);
    just after it.

    Finally, scanf() is a tricky function that should not be used by newbies (actually only a bunch of gurus know exactly how to use it). Better to stick to fgets() to get the line and strtol() or the like to convert the string into a number.

    At minimum, you should test the value returned by scanf(). In your case, a value that is not 1 denotes an input error. (Details in your C-book)
    Last edited by Emmanuel Delaha; 01-01-2005 at 04:24 AM. Reason: details added
    Emmanuel Delahaye

    "C is a sharp tool"

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