C compile error: unknown type name 'node'

Question

The compiler gives the following error with the code below, at the location of the added comment:

error: unknown type name 'node'

#include <stdio.h>

typedef struct node
{
    int info;
    node *sig; //<-- error: unknown type name 'node'
} nodeL;

int main(void) {
    nodeL n;
    printf("%x\n", n.info);

    return 0;
}

How can I solve it?

This is a simple typographical error, so it should be closed. — machine_1, Sep 13 '17 at 16:31
It seems that everyone focused on the (now fixed) nodo/node typo, while the actual problem is that `sig` should be of the type `struct node`, or `nodeL` with a forward declaration. — Yun, Sep 18 '21 at 10:13

score 2 · Answer 1 · answered Sep 13 '17 at 16:37

You must keep in mind that C compiler don't know what is node or nodo (you typed it wrong in the struct name probably), it's not a C primary type. At this point nodo is a struct type and you must "say" it to the compiler, like:

typedef struct nodo
{
    int info;
    struct nodo *sig; 
} nodeL;

The atribute nodo *sig; inside the struct declares a member sig that is a defined pointer to the struct type.

Mahonri Moriancumer · Answer 2 · 2017-09-13T16:33:35.470

-1

typedef struct nodo
{
    int info;
    struct nodo *sig; // Rather than: node *sig;
} nodeL;

It looks like your structure name node is what you are referencing inside the structure. nodo not node.

Perhaps there is a mis-understanding that nodo (or node) is a C type. It is not a type. However struct nodo is defined in the question code.

edited Sep 13 '17 at 16:33

answered Sep 13 '17 at 16:26

Mahonri Moriancumer

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your answer is just code with no explanation as to why you've changed what you've changed – Chris Turner Sep 13 '17 at 16:29

C compile error: unknown type name 'node'

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