designated Initialization of a Node with a pointer (C++)

Question

When creating a new node in a linked list, is it legal to use designated initializers to initialize the members of the node as mentioned below? Is there any repercussion in doing so and what would be a better way to achieve the same result? (lang : C++)

Node *temp = new Node{.data = value, .next = NULL};

struct Node
{
    int data;
    Node *next;
};

That looks like C++ to me. If so you should remove the C tag and add a C++ one. — dmuir, Feb 18 '21 at 10:16
`Node *temp = new Node{.data = value, .next = NULL};` is C++ but you tagged `C`, so there is a contradiction. Please clarify. — Jabberwocky, Feb 18 '21 at 10:29
Yes I used the the new keyword here by mistake, I should have used malloc. sorry for the miscommunication — Sameer Ahmed, Feb 18 '21 at 10:33
@SameerAhmed well, then [edit] the question. Don't explain what you should have done but do it. — Jabberwocky, Feb 18 '21 at 10:33
I am confused because you say it is C++, question is now tagged as C++, but you accepted a C answer. What is it really? — 463035818_is_not_an_ai, Feb 18 '21 at 11:30
@pqans Designated initialisers are a C++ standard (since C++20). — eerorika, Feb 18 '21 at 12:11
@SameerAhmed `I should have used malloc`, `lang : C++`: You shouldn't use `malloc` in C++. Nor should you use `NULL`. — eerorika, Feb 18 '21 at 12:13
@eerorika: Sorry, i see you're right. I wasn't aware of. Now i am. — Wör Du Schnaffzig, Feb 18 '21 at 12:30
@largest_prime_is_463035818 the code is technically in c++ since I used the new keyword, I just wanted to know about designated initializers. The answer I accepted seems to work (with a different method) so I am not too bothered about the specifics. — Sameer Ahmed, Feb 22 '21 at 07:18

score 1 · Accepted Answer · answered Feb 18 '21 at 10:25

1

I think you can use function as a constructor.

Node* newFunction(int data) { 
  Node* newNode = malloc(sizeof(Node));
  newNode->data=data;
  newNode->next=NULL;
  return newNode;
}

And after that, you can use in the main part like that;

Node* newNode = newFunction(5);

answered Feb 18 '21 at 10:25

Ogün Birinci

598
3
11

`malloc` cannot construct C++ objects. It merely allocates memory – 463035818_is_not_an_ai Feb 18 '21 at 15:45
@largest_prime_is_463035818 when I write this solution, he asked for the C language. – Ogün Birinci Feb 18 '21 at 16:21
I know but meanwhile tags have been changed and OP clarified that their code is C++. I just wanted to leave a comment, because in C++ this answer can be considered wrong, not your fault – 463035818_is_not_an_ai Feb 18 '21 at 16:22
Yeah, you're right. I did not realize the tags has been changed until you inform me. I guess when the tag change, we can not take any notification. – Ogün Birinci Feb 18 '21 at 16:35

designated Initialization of a Node with a pointer (C++)

1 Answers1