Two or more data types in declaration specifiers error [closed]

Closed. This question is not reproducible or was caused by typos. It is not currently accepting answers.

---

This question was caused by a typo or a problem that can no longer be reproduced. While similar questions may be on-topic here, this one was resolved in a way less likely to help future readers.

Closed 6 years ago.

Improve this question

I am pretty new to C.

I am getting this error:

incompatible implicit declaration of built-in function ‘malloc’

Even when I fix the code based on the answers to include <stdlib.h>, I still get:

two or more data types in declaration specifiers

开发者_StackOverflow

When trying to do this:

struct tnode
{
    int data;
    struct tnode * left;
    struct tnode * right;
}

struct tnode * talloc(int data){
    struct tnode * newTnode;
    newTnode = (struct tnode *) malloc (sizeof(struct tnode));
    newTnode->data = data;
    newTnode->left = NULL;
    newTnode->right = NULL;
    return newTnode;
}

How do I fix it?

---

You have to put ; behind the struct declaration:

struct tnode
{
    int data;

    struct tnode * left;
    struct tnode * right;
}; // <-- here

---

Your original error was because you were attempting to use malloc without including stdlib.h.

Your new error (which really should have been a separate question since you've now invalidated all the other answers to date) is because you're missing a semicolon character at the end of the struct definition.

This code compiles fine (albeit without a main):

#include <stdlib.h>

struct tnode
{
    int data;

    struct tnode * left;
    struct tnode * right;
};

struct tnode * talloc(int data){
    struct tnode * newTnode;
    newTnode = (struct tnode *) malloc (sizeof(struct tnode));
    newTnode -> data = data;
    newTnode -> left = NULL;
    newTnode -> right = NULL;
    return newTnode;
}

---

"Implicit declaration" means that you're trying to use a function that hasn't been formally declared.

You probably forgot: #include <stdlib.h> which includes the function declaration for malloc.

---

Do you have the appropriate header file included?

That is, is there a line at the top of your file that says

#include <stdlib.h>

Hope this helps.

---

Ensure you have included the header file that contains the definition for malloc():

#include "stdlib.h"