Member Avatar for vskumar19

Hi all,

I have a structure for which array of objects are created
Now i want to return that array of objects to a function just like below:

struct mystruct s[5];
.
. code
.

return s;

in the function i captured using *s
void myfun(mystruct *s)

but i am unable to retrieve values using this s
c

If there is anything wrong in my syntax.. can anyone help me out to retrieve the structure values in the function

Thanks

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  • Latest Post Latest Post by Isaac Remuant

Dani AI

Generated

Quick diagnosis tied to the posted snippets: the array in main is an array of structs, but the function signature you used expects an array of pointers. That mismatch makes expressions like m[0]->x wrong for your data. Also, when an array is passed to a function it decays to a pointer to the first element — so you must either accept that pointer (and the element count) or use a container/type that preserves size. was pointing in this direction; ’s code shows the common confusion between “array of T” and “array of T*”.

Safer, modern alternatives (examples):

std::vector<mystruct> make_structs()
{
    std::vector<mystruct> v(3);
    v[0].x = 2;
    return v; // efficient: move semantics
}

For fixed-size arrays and compile-time size preservation:

template<size_t N>
void myfun(mystruct (&arr)[N])
{
    // arr has known size N inside the function
}

If you must work with raw arrays allocated on the heap, prefer smart pointers:

auto p = std::make_unique<mystruct[]>(3);
// use p[0].x ...
return p; // returns ownership safely (C++14+)

Practical tips and cautions:

  • Do not return a pointer to a local (stack) array — that yields undefined behavior.
  • If function receives an array, pass the length too (or use std::vector/std::span/std::array so size is available).
  • Use . for struct values (elem.x) and -> only when elements are pointers.
  • Compile with warnings enabled (e.g., -Wall -Wextra) and use AddressSanitizer/Valgrind for runtime issues.

These patterns avoid the pointer/pointer-to-pointer trap seen in the thread and give safer, clearer ownership and lifetime semantics than raw arrays.

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Member Avatar for Isaac Remuant

The wording of this post is weird. Maybe posting the relevant code in CODE tags might help.
You can't return arrays. You can return a pointer to an array though.
What do you want to do? Use that array within a function? In that case, I recommend you to google how to pass an array as a paramater in a function.

Member Avatar for vskumar19

<CODE>
struct mystruct
{
int x;
};

int main()
{
mystruct m[3];
m[0].x=2;
m[1].x=3;
m[2].x=4;
myfun(m);
}

void myfun(mystruct *m[])
{
cout<<m[0]->x;
}
</CODE>

this the type of functionality that i need..
but unable to get it...
wht could be other possible way ?

Member Avatar for Isaac Remuant

correct syntax:

<return type> <function name> (<type> <array name>[]);

You're mixing up concepts.

remember that arrays are passed automatically by reference in c++. I suggest you read about references, pointers and passing arrays into functions.
http://www.learncpp.com/cpp-tutorial/611-references/
http://www.learncpp.com/cpp-tutorial/612-references-vs-pointers-and-member-selection/
etc.


This will do what you ask:

#include <iostream>

using namespace std;

struct mystruct
{
int x;
};

void myfun(mystruct m[])
{
cout<<m[0].x; 
}

int main()
{
mystruct m[3];
m[0].x=2;
m[1].x=3;
m[2].x=4;
myfun(m);
}
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