c - 链接列表无法正常工作

Question

这是一个基本的链表，它添加节点然后打印它们，但由于某种原因它无法正常工作。根据我的测试，它在打印列表后失败，直到打印工资时错误地打印了数字，然后终止。

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

typedef struct node_s {                                          
        char job_title[25];
        double hourly_wage;
        struct node_s *next;
} node_t;

void print_list(node_t *list);
void add_node(node_t **head, char *title, double hwage);

int main()                                                
{

      node_t *list;
      list = NULL;

       add_node(&list, "Programmer", 32.35);             
       print_list(list); 
       add_node(&list, "Analyst", 25.80);       
       print_list(list);             
       add_node(&list, "Technician", 17.50);
       print_list(list); 
       add_node(&list, "Clerk", 12.00);
       print_list(list); 
       add_node(&list, "Manager", 53.58);
       print_list(list);     

       return(0);
}                                                          

void print_list(node_t *list){
    node_t *current;
    if (current == NULL) {
        printf("\n");
    }else{
        printf("The job is called:%s\n", current->job_title); 
        printf("The job pays %d hourly.\n", current->hourly_wage);
        print_list(current->next);
    }
}

void add_node(node_t **head, char *title, double hwage){
    node_t *current = head;
    node_t *newNode = (node_t *) malloc(sizeof(node_t));
    if (newNode == NULL) {
        printf("malloc failed\n");
        exit(-1);
    }    

    strcpy(newNode->job_title, title);
    newNode->hourly_wage = hwage;
    newNode->next = NULL;

    while (current->next) {
        current = current->next;
    }    
    current->next = newNode;
}

Answer 1

在以下代码部分:

void print_list(node_t *list){
    node_t *current;
    if (current == NULL) {

您正在将当前指针的未初始化值与 null 进行比较。我想你忘了给它赋值:

current = list;

在 if 指令之前。