dynamically changing an array size in C

This is a discussion on dynamically changing an array size in C within the C Programming forums, part of the General Programming Boards category; There was another thread on this topic that I was going to reply to but it was closed. This is ...

  1. #1
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    dynamically changing an array size in C

    There was another thread on this topic that I was going to reply to but it was closed.


    This is my code:

    Code:
    #include <stdio.h>
    
    
    int main()
    {
    
    int *result;
    
    result = (int *) malloc(3);
    
    
    result[0] = 5;
    result[1] = 2;
    result[2] = 3;
    
    free(result);
    
    
        printf("%d \n", result[0]);
    
        return 0;
    }
    When using printf to display the value of result[0], it always says the value is 0, not 5. It displays result[1] and result[2] correctly as 2 and 3.

    What is wrong?

  2. #2
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    nevermind, i already figured it out.

    The free(result) function was causing it.

  3. #3
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    You are allocating 3 bytes, an int is most probably 4 bytes. So you will need: malloc( 3 * sizeof(int) );

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