pointer to a structure

From: Ravi kumar.N (ravikumar.n_at_sunlux-india.com)
Date: 11/21/04

  • Next message: Siddharth Taneja: "Re: pointer to a structure" 
    Date: 20 Nov 2004 22:21:57 -0800

    Respected Experts,
                          Iam Ravikumar.N, working as a juniour software
    Engineer.I have a query regarding pointer to a structure.

      
       1) Memory will be allocated to a structure when a variable is
    declared to it.

       2) Consider the following example.

             struct a{
                 int c;
                 int d;
            }

            struct a e; (When we declare 'e' as a structure variable,
    memory will be allocated to structure. Here no need of malloc for
    memory allocation)

       3)When we use a pointer to a structure . eg. struct a *g;
            The following things has to be done to access the structure
    member.
      
            3.1) Once we declare a pointer to the structure, memory
    allocation has to be done using malloc.
         
              e.g. g = (struct a*)malloc(sizeof(struct a));

           3.2)If we try to access the structure member without the above
    step done, during run-time an error saying "Memory could not be
    referenced" will be displayed.

      My query is as follows

        4)Since memory to the structure will be allocated as soon as we
    declare a structure variable, why malloc has to be done for pointer to
    the structure and why not for the structure variable like "struct a
    e";

  • Next message: Siddharth Taneja: "Re: pointer to a structure"

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