Change array length

This is a discussion on Change array length within the C Programming forums, part of the General Programming Boards category; On beginning I define two arrays a[5]; b[5]; after this I need next array C c[5]; but when I have ...

  1. #1
    Registered User
    Join Date
    Nov 2010
    Posts
    6

    Change array length

    On beginning I define two arrays

    a[5];
    b[5];

    after this I need next array C

    c[5];

    but when I have c[5] = a[5] + b[5]

    I have overflow of array C.

    how can I change length of array C in loop, I don't change C if I don't have overflow

  2. #2
    Registered User
    Join Date
    Sep 2008
    Posts
    58
    It would be c[4] = a[4] + b[4].

  3. #3
    Registered User
    Join Date
    Sep 2006
    Posts
    8,868
    Remember that arrays in C begin with index 0, so array[5] gives you indeces 0-4 only.

  4. #4
    Registered User
    Join Date
    Nov 2010
    Posts
    6
    I know that a[0] is first element of array

    I have need for something like this:
    Code:
    a[5] = {9,9,9,9,9,9}
    +
    b[5] = {8,8,8,8,8,8}
    =
    c[5+1] = {1,8,8,8,8,8,7}
    that mean c[i+1] = a[i] + b[i]
    but 1 in [i+1] is conditioned by add, it not always present
    Code:
    a[5] = {4,4,4,4,4,4}
    +
    b[5] = {4,4,4,4,4,4};
    =
    c[5] = {8,8,8,8,8,8};
    in this case I don't have need for +1 in c[i]

  5. #5
    Registered User
    Join Date
    Jun 2005
    Posts
    6,313
    Set the length of array c to be 6 and, in cases where the length of the result is 5, make the first element zero.
    Right 98% of the time, and don't care about the other 3%.

  6. #6
    Registered User
    Join Date
    Nov 2010
    Location
    xian china
    Posts
    31
    define array c longer length.
    Code:
    int c[255] = {0};
    then when you do " a[5] = {4,4,4,4,4,4}+b[5] = {4,4,4,4,4,4};"
    the result put into c can be begin from 0,
    like c[0] = a[4]+b[4],c[1] = a[3]+b[3]...
    Last edited by Jesius; 11-28-2010 at 02:34 AM.

  7. #7
    Banned
    Join Date
    Aug 2010
    Location
    Ontario Canada
    Posts
    9,547
    Quote Originally Posted by miroslavgojic View Post
    On beginning I define two arrays

    a[5];
    b[5];

    after this I need next array C

    c[5];

    but when I have c[5] = a[5] + b[5]

    I have overflow of array C.

    how can I change length of array C in loop, I don't change C if I don't have overflow
    Are you sure you're not tripping over that old C problem where the number of elements does not equal the numbers of the elements?

    Array elements always number from 0, not from 1, so a[5] has elements numbered 0 ,1 ,2, 3, 4

    There is no element #5... but there is The 5th Element

Popular pages Recent additions subscribe to a feed

Similar Threads

  1. length of dynamic array
    By budala in forum C Programming
    Replies: 12
    Last Post: 02-12-2011, 01:25 PM
  2. Replies: 16
    Last Post: 05-29-2009, 07:25 PM
  3. Replies: 2
    Last Post: 07-11-2008, 07:39 AM
  4. array length question
    By cs_newbie in forum C Programming
    Replies: 24
    Last Post: 10-12-2006, 09:10 AM
  5. array length
    By Wick in forum C++ Programming
    Replies: 3
    Last Post: 08-30-2003, 04:53 PM

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21