Today learned a linked list, on the heap manual opening and assignment can run normally, but in the end tip warning: cancel the NULL pointer "node" on the reference, can't think of is where there is a problem, to help you, as a novice, please light spray

 # define _CRT_SECURE_NO_WARNINGS 
#include  
#include  
#include  

Struct the Teacher 
{
Char name [64]. 
int age; 
Char sex [12]. 
Struct the Teacher * LinkNode; 
}; 

Void distr () 
{
Struct the Teacher * node1=malloc (sizeof (struct the Teacher)); 
Struct the Teacher * 2=malloc (sizeof (struct the Teacher)); 
Struct the Teacher * node3=malloc (sizeof (struct the Teacher)); 
Struct the Teacher * node4=malloc (sizeof (struct the Teacher)); 
Struct the Teacher * node5=malloc (sizeof (struct the Teacher)); 
Struct the Teacher * node6=malloc (sizeof (struct the Teacher)); 

//manual for each teacher's attribute assignment 
Node1 - & gt; Age=24; Strcpy (node1 - & gt; The name, "Mr Li"); Strcpy (node1 - & gt; Sex, "male"); 
2 - & gt; Age=41; Strcpy (2 - & gt; The name, "Mr Wu"); Strcpy (2 - & gt; Sex, "female"); 
Node3 - & gt; Age=32; Strcpy (node3 - & gt; The name "zhou"); Strcpy (node3 - & gt; Sex, "male"); 
Node4 - & gt; Age=34; Strcpy (node4 - & gt; The name, "miss huang"); Strcpy (node4 - & gt; Sex, "male"); 
Node5 - & gt; Age=28; Strcpy (node5 - & gt; The name, "wang"); Strcpy (node5 - & gt; Sex, "female"); 
Node6 - & gt; Age=33; Strcpy (node6 - & gt; The name, "xue teacher"); Strcpy (node6 - & gt; Sex, "female"); 

//build relationships in the list 
Node1 - & gt; LinkNode=2; 
2 - & gt; LinkNode=node3; 
Node3 - & gt; LinkNode=node4; 
Node4 - & gt; LinkNode=node5; 
Node5 - & gt; LinkNode=node6; 
Node6 - & gt; LinkNode=NULL; 

//traversing and print the list 
Struct the Teacher * Ptemp=node1; 
While (Ptemp!=NULL) 
{
The teacher's name is: printf (" % s \ t gender is: % s \ t age is: % d \ n ", Ptemp - & gt; The name, Ptemp - & gt; Sex, Ptemp - & gt; The age); 
Ptemp=Ptemp - & gt; LinkNode; 
} 

//release list 
Free (node6); Free (node5); Free (node4); Free (node3); Free (2); Free (node1); 

} 


Int main () 
{
Distr (); 

system("pause"); 
Return EXIT_SUCCESS; 
} 

CodePudding user response:

Struct the Teacher * node1= (struct the Teacher *) malloc (sizeof (struct the Teacher));
Several other so are processing

No problem

CodePudding user response:

1/f, bosses, this method still not VS2019 or prompt the same warning,,, thank you very much for the reply of

CodePudding user response:

Put the warning posted, where the line? What is specific textual warning?

CodePudding user response:

 severity code shows the project file line prohibits display status details 
Warning C6011 cancel to NULL pointer "node1" reference, day06 C: \ USERS/ADMINISTRATOR/DESKTOP/one-way dynamic linked list. 25 C 

CodePudding user response:

CodePudding user response:

Warning meaning is to let you check the pointer is NULL mean
You this is VS2019?
Under VS2019 strcpy become strcpy_s and suggest what time into such English description

If (node1!=NULL) {
Node - & gt; Age=...
}

CodePudding user response:

Or, unified before 25 line assignment write a line
If (NULL==node1 | | NULL==2 | |... ) return;

This test it is to let you to have a NULL after malloc judgment then do other processing