Why there is an error with linked list, when i try to enter some value in int d?

Question

I'm new in coding and I was wondering why this code crashes when I enter some value. There are some tutorials for this, but I don't get it.

Can someone explain linked lists very simple, please?

#include <stdio.h>
#include <stdlib.h>

typedef struct node{
    int data;
    struct node *next;
}tnode;

int main()
{
    tnode *head=NULL;
    tnode *new=(tnode*)malloc(sizeof(tnode));
    int d;
    scanf("%d", d);
    new->data=d;
    new->next=NULL;
    if(head==NULL)
    {
        head=new;
        return;
    }

    return 0;
}

Note that this time, the problem is nothing to do with linked lists — it is a basic typo in the use of `scanf()`. — Jonathan Leffler, May 25 '20 at 00:06

score 1 · Accepted Answer · answered May 24 '20 at 23:43

I saw a few problems in there, I think.

This is not an error technically, but using new as an identifier (for a variable or method name) is not recommended. If one were to try to use this in a c++ program it would break.
scanf("%d",d) should be scanf("%d",&d); it’s expecting the address of the variable where to store the input value.
It doesn’t make much sense to return in the if statement, but if you do, you should specify a return code (your last return line has 0 as the code; you could use that, or pick a different number if you want).

Why there is an error with linked list, when i try to enter some value in int d?

1 Answers1