使用结构指针读取字符串时c中的结构指针问题 [英] structure pointer problem in c when reading string using structure pointer

问题描述

struct book
{
	char name[50];
	char author[50];
	int page;
	float price;
};
int main()
  {
  	 struct book *x;
  	 printf("name : ");
  	 gets(x->name);
  	 printf("author : ");
  	 gets(x->author);
  	 printf("page : ");
  	 scanf("%d",&x->page);
  	 printf("price : ");
  	 scanf("%f",&x->price);
  	 printf("\n%s\t%s\t%d\t%f",x->name,x->author,x->page,x->price);
  	 getch();
  	 return 0;
  }

这段代码无法正常工作，并给出了分段错误

this code is not working properly and giving a segmentation fault

推荐答案

我对它给出分段错误并不感到惊讶.在main中，您拥有；

I''m not surprised it gives a segmentation fault. In main you have;

  	 struct book *x;
  	 printf("name : ");
  	 gets(x->name);
...

因此，您已经创建了指针x，但是它没有指向任何内容，因此存在段错误.您需要对其进行初始化，以便它指向实际的内存结构.这是通过调用malloc来完成的，因此:

So you have created the pointer x but it does not point to anything, hence the seg fault. You need to initialise it so that it points to an actual memory structure. This is done by a call to malloc thus:

struct book *x;
    // allocate a new book structure on the heap
    x = (struct book *)malloc(sizeof(struct book));
printf("name : ");
gets(x->name);

您没有初始化结构指针x.我猜您正在通过查看问题标签来使用C ++.用这种方式做.

You didn''t initialize the structure pointer x. I guess you''re using C++ by seeing your question''s tags. Do it in this way.

struct book *x;
x = new book;
printf("name : ");
.....

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