C语言为什么输出出栈的字符串时会输出乱码如0xz，是因为没有正确分配内存吗？希望大佬们解答

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
struct LLNode
{
    char ID[5];
    struct LLNode *next;
};

struct LLNode * createNode(char val[5]) 
{
    struct LLNode *temp;
    temp=(struct LLNode *)malloc(sizeof(struct LLNode));
    temp->next=NULL;
    strcpy(temp->ID, val);
    return temp;
};

void push(char* val, struct LLNode *head)
{
    struct LLNode *temp;
    temp = createNode(val);
    temp->next = head->next;
    head->next = temp;
}

char* pop(struct LLNode *head)
{
    struct LLNode *temp;
    char *val = (char *)malloc(5*sizeof(char));
    strcpy(head->next->ID, val);
    temp = head->next;
    head->next = head->next->next;
    free(temp);
    return val;
}

char nothing(struct LLNode *head, struct LLNode *tail)
{
    if(head->next == NULL) 
        return 1;
    else
        return 0;
}

int main()
{
    char* value = (char *)malloc(5*sizeof(char));
    struct LLNode *head = NULL;
    struct LLNode *tail = NULL;

    head = createNode("");
    tail = createNode("");

    head->next = tail;
    printf("head->ID = %s\n", head->ID);

    push ("C201", head);
    printf("head->next->ID = %s\n",head->next->ID) ;  

    push ("C202", head);
    printf("head->next->ID = %s\n",head->next->ID) ;  

    push ("C203", head);
    printf("head->next->ID = %s\n",head->next->ID) ;  

    push ("C204", head);
    printf("head->next->ID = %s\n",head->next->ID) ;  

    push ("C205", head);
    printf("head->next->ID = %s\n",head->next->ID) ;  
    
    for (int i=0; i<3; i++)
    {
        value = (char *)malloc(5*sizeof(char));
        strcpy(value, pop(head));
        printf("The value pop = %s\n", value);
        printf("head->next->ID= %s\n",head->next->ID);
        free(value);
    }
    
    if (nothing(head,tail))
        printf("The stack is empty");

    printf("Remaining IDs:");
    struct LLNode *curr = head;
    while (curr) 
    {
        printf("%s ",curr->ID);
        curr = curr->next;
    }
    return 0;
}

输出：

char* pop(struct LLNode *head)
{
    struct LLNode *temp;
    char *val = (char *)malloc(5*sizeof(char));
    //strcpy(head->next->ID, val);
	
    strcpy( val,head->next->ID);
    temp = head->next;
    head->next = head->next->next;
    free(temp);
    return val;
}

拷贝反了。

strcpy(head->next->ID,val);

改为

strcpy( val,head->next->ID);

试试

char* pop()函数中，定义了val,也申请了内存，但是整个函数一直没使用这个变量，只在最后return val，它里面是什么东西谁都不知道，在后面strcpy中，第二个参数是pop()函数的返回值，所以复制的内容谁也不知道是什么

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