List p=(List)malloc(sizeof(struct Node))
时间: 2023-06-14 12:04:21 浏览: 91
这行代码是在C语言中动态分配一个结构体类型为Node的内存空间,并将其首地址赋值给指针p。
具体来说,malloc()函数会在内存堆中分配一块大小为sizeof(struct Node)的连续内存空间,并返回这块内存空间的首地址。然后,将这个地址强制转换为List类型的指针,并将其赋值给变量p。
这样做的目的是为了在程序运行时动态地创建一个链表节点,并且可以通过p来访问这个节点的各个成员变量。需要注意的是,这个节点的成员变量的值都是不确定的,需要在程序中进行初始化。同时,使用完这个节点后,还需要使用free()函数释放其内存空间,以避免内存泄漏。
相关问题
struct Node *newNode = (struct Node*)malloc(sizeof(struct Node))
This line of code allocates memory for a new node in a linked list.
Here's what it does:
- `struct Node*` specifies the data type of the new node, which is a pointer to a struct Node.
- `malloc(sizeof(struct Node))` dynamically allocates memory for the new node with the size of `struct Node`.
- `(struct Node*)` casts the pointer returned by `malloc` to a `struct Node*` data type.
- The resulting pointer is assigned to the pointer variable `newNode`.
Overall, this line of code creates a new node in memory that can be used to store data in a linked list.
malloc(sizeof(struct Node))
This is a C code that allocates memory for a new node in a linked list data structure.
The malloc() function is used to dynamically allocate memory in C. sizeof(struct Node) calculates the size of the memory block required for the structure Node defined in the code. This size is then passed as a parameter to malloc(), which returns a void pointer pointing to the allocated memory block.
The code snippet can be used to create a new node in a linked list by initializing the struct fields with appropriate values. For example:
struct Node *newNode = (struct Node *) malloc(sizeof(struct Node));
newNode->data = 10;
newNode->next = NULL;
This creates a new node with data value 10 and NULL next pointer. The newNode pointer can then be used to link it with other nodes in the linked list.