my list error!!

[wbgxx]

#include<iostream>
using namespace std;
class list
{
public:
	int number,score;
	char name[10];
	class list*next;
};

void create(list* head)
{
	list* p=head;
    while(1)
	{
		list* pp=new node;
		if(!pp)
		{
			cout<<"erroe"<<endl;
			exit(1);
		}
		cout<<"Please input the student ID：";
		cin>>pp->number;
		if(pp->number==0)
			break;
		else
		{
			
			cout<<"Pleast input the studnet name";
			cin>>pp->name;
			cout<<"Please input score：";
			cin>>pp->score;
			p->next=pp;
			p=pp;
		}
		
	}
}

void show(list* head)
{
	list* ptr=head;
	cout<<"\n --  STUDNET  ---"<<endl;
	cout<<"ID\tNAME\tscore\n============================"<<endl;
	while(ptr!=NULL)
	{
		cout<<ptr->number<<"\t"<<ptr->name<<"\t"<<ptr->score<<endl;
		ptr=ptr->next;
		
	}
}
		
int main()
{
	list* head=NULL;
	create(head);
	show(head);
	return 0;
}

[wbgxx]

there is a error in runtime

[weaknessforcats]

It looks like head in NULL in main() after the return from create. Then you use the null pointer with the -> operator in show and die right there.

You need to pass the address of head to create. The argument to create should be list** so you can put the address of the created node into head by using *head = new node in create.

Do you have a debugger you can use? Usually you can step through code and see exactly where it fails.

[johny10151981]

In line 56 you have called create function with variable head which is null

In line 13 you have assigned
p = head
which mean p is null;
but in line 33 you did
p->next=pp;
but still p is null. You cant do that. Try allocate some memory.

But you should also check your logic. Cause in line 34 you did
p=pp;

So re-think what do want to do...
I think your logic will be something like that... First before line 56 allocate some memory for head(use malloc).

in the function do something like that (or better you think)
while()
{
...
some logic to control loop.
...
pp = new ...();
p->next=pp;
p->...=your_data( );
}while()

above logic is not complete. You better complete yourself. (I am not that good)

Best Regards,
JOHNY