w3resource

C Exercises: Show a pointer to an array which contents are pointer to structure

C Pointer : Exercise-20 with Solution

Write a program in C to show a pointer to an array whose contents are pointers to structures.

Visual Presentation:

C Exercises: Pictorial: Show a pointer to an array which contents are pointer to structure.

Sample Solution:

C Code:

#include <stdio.h>

// Defining a structure for employee details
struct employee {
    char *empname;  // Employee name (string pointer)
    int empid;      // Employee ID (integer)
};

// Main function
int main() {
    // Displaying the purpose of the program
    printf("\n\n Pointer : Show a pointer to an array which contents are pointer to structure :\n");
    printf("-----------------------------------------------------------------------------------\n");

    // Initializing employee structures with values
    static struct employee emp1 = {"John", 1001}, emp2 = {"Alex", 1002}, emp3 = {"Taylor", 1003};

    // Creating an array of pointers to struct employee
    struct employee (*arr[]) = {&emp1, &emp2, &emp3};

    // Creating a pointer to an array of pointers to struct employee
    struct employee (*(*pt)[3]) = &arr; // pt stores the address of the array of pointers

    // Printing employee name using pointer to an array of pointers to structure
    printf(" Employee Name : %s \n", (**(*pt + 1)).empname);

    // Explanation for the printed employee name
    printf("---------------- Explanation --------------------\n");
    printf("(**(*pt+1)).empname\n");
    printf("= (**(*&arr+1)).empname   as pt=&arr\n");
    printf("= (**(arr+1)).empname     from rule *&pt = pt\n");
    printf("= (*arr[1]).empname       from rule *(pt+i) = pt[i]\n");
    printf("= (*&emp2).empname        as arr[1] = &emp2\n");
    printf("= emp2.empname = Alex       from rule *&pt = pt\n\n");

    // Printing employee ID using pointer to an array of pointers to structure
    printf(" Employee ID :  %d\n", (*(*pt + 1))->empid);

    // Explanation for the printed employee ID
    printf("---------------- Explanation --------------------\n");
    printf("(*(*pt+1))-> empid\n");
    printf("= (**(*pt+1)).empid     from rule -> = (*).\n");
    printf("= emp2.empid = 1002\n");
    printf("\n\n");

    return 0;
}

Sample Output:

 Pointer : Show a pointer to an array which contents are pointer to structure :                               
-----------------------------------------------------------------------------------                           
 Exmployee Name : Alex                                                                                        
---------------- Explanation --------------------                                                             
(**(*pt+1)).empname                                                                                           
= (**(*&arr+1)).empname   as pt=&arr                                                                          
= (**(arr+1)).empname     from rule *&pt = pt                                                                 
= (*arr[1]).empname       from rule *(pt+i) = pt[i]                                                           
= (*&emp2).empname        as arr[1] = &emp2                                                                   
= emp2.empname = Alex       from rule *&pt = pt                                                                 
                                                                                                              
 Employee ID :  1002                                                                                          
---------------- Explanation --------------------                                                             
(*(*pt+1))-> empid                                                                                            
= (**(*pt+1)).empid     from rule -> = (*).                                                                   
= emp2.empid = 1002 

Flowchart:

Flowchart: Show a pointer to an array which contents are pointer to structure

C Programming Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous:> Write a program in C to show a pointer to union.
Next: Write a program in C to print all the alphabets using pointer.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Become a Patron!

Follow us on Facebook and Twitter for latest update.

It will be nice if you may share this link in any developer community or anywhere else, from where other developers may find this content. Thanks.

https://w3resource.com/c-programming-exercises/pointer/c-pointer-exercise-20.php