Accessing Nested structure variable

Question

When I tried to compile the following program, it gives me no output on screen:

#include<stdio.h>
int main ()
{
struct d1
{
char arr [10];
int num;
};

struct d2
{
struct d1 name;
int age;
}p1;

p1.name={("JANE",8)};
printf ("%s",&p1.name.arr[0]);
}

I think problem is due to line p1.name={("JANE",8)}; But I think I have written everything right. By writing this line I tried to assign value to a member,"name" of variable p1 having structure type d2. And as name is itself a structure of type d1 having two members, so I assigned two values JANE and 8 to arr [10] and num members of name respectively.

I even tried with

p1.name={{"JANE",8}}; //For this it gives error

p1.name={("JANE",8),20}; //For this it compiles but no output

p1.name={{"JANE",8},20}; //again error

That 20 is value of p1's member "age". While trying to print value p1.name.age it gives 0 instead of20.

What's wrong? Is there any syntax error or a conceptual error?

You need typecast, because compiler does not know, what literal {"JANE",8} is. Use p1.name=(struct d1){"JANE",8}; — Roman Hocke
– Roman Hocke, Commented Jan 30, 2019 at 16:40
@RomanHocke It is not typecasting. It is the compound literal — 0___________
– 0___________, Commented Jan 30, 2019 at 16:45
@Avi - we should not answer it. You even did not bother to format the code — 0___________
– 0___________, Commented Jan 30, 2019 at 16:46

0___________ · Accepted Answer · 2019-01-30 16:46:43Z

3

The form you use is only allowed if you initilize the structure. You need to use compound literals.

#include<stdio.h>

int main ()
{

    struct d1
    {
        char arr [10];
        int num;
    };

    struct d2
    {
        struct d1 name;
        int age;
    }p1;

    p1.name=(struct d1){"JANE",8};
    printf ("%s",p1.name.arr);
}

edited Jan 30, 2019 at 16:46

answered Jan 30, 2019 at 16:39

0___________

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1 Comment

Roman Hocke Over a year ago

The printf() is okay, he has &...[0].

bruno · Accepted Answer · 2019-01-30 16:40:42Z

2

if is is an initialization do directly :

#include<stdio.h>

int main ()
{
  struct d1
  {
    char arr [10];
    int num;
  };

  struct d2
  {
    struct d1 name;
    int age;
  }p1 = {{"JANE",8}, 20};

  printf ("%s",&p1.name.arr[0]);
}

p1.name.num is 8 and p1.age is 20

note &p1.name.arr[0] can be p1.name.arr

answered Jan 30, 2019 at 16:40

bruno

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