🍓结构体的运用

🍓结构体与指针

struct Book
{
	int isbn;			//刊号
	char author;		//作者
	float price;		//单价
}

struct Book book1 = {12345678,"lqy",78.50f};

struct 	Book *pBook = &book1;

1️⃣指针解引用方式

(*pBook).isbn

printf("ISBN: %d\n",(*pBook).isbn);
printf("Author: %s\n",(*pBook).author);
printf("Price: %.2f\n",(*pBook).price);

ISBN: 12345678
Author: lqy
Price: 78.50

2️⃣非指针解引用方式

pBook->isbn

printf("ISBN: %d\n",pBook->isbn);
printf("Author: %s\n",pBook->author);
printf("Price: %.2f\n",pBook->price);

ISBN: 12345678
Author: lqy
Price: 78.50

int *pIsbn = &book1.isbn;			//指向成员isbn指针
char *pAuthor = book1.author;		//指向成员author指针
float *pPrice = &book1.price;		//指向成员price指针

🍓结构体与数组

struct Book books[3] = {{12345678,"lqy",78.50f}
						{23456789,"lqy1",75.50f}
						{34567890,"lqy2",80.50f}};

for(int i = 0;i < 3;++i)
{
	printf("ISBN: %d\n",books[i].isbn);
	printf("Author: %s\n",book[i].author);
	printf("Price: %.2f\n",book[i].price);
	printf("----------------------------\n");
}

ISBN: 12345678
Author: lqy
Price: 78.50
----------------------------
ISBN: 23456789
Author: lqy1
Price: 75.50
----------------------------
ISBN: 34567890
Author: lqy2
Price: 80.50
----------------------------

for(int i = 0;i < 3;++i)
{
	printf("ISBN: %d\n",(*(books + i)).isbn);
	printf("Author: %s\n",(*(books + i)).author);
	printf("Price: %.2f\n",(*(books + i)).price);
	printf("----------------------------\n");
}

for(int i = 0;i < 3;++i)
{
	printf("ISBN: %d\n",(books + i)->isbn);
	printf("Author: %s\n",(books + i)->author);
	printf("Price: %.2f\n",(books + i)->price);
	printf("----------------------------\n");
}

🍓结构体与函数

struct Rect					//矩形结构体
{
	float length;			//长
	float width;			//宽
	float area;				//面积	
}

void calculate(struct Rect rect)
{
	rect.area = rect.length * rect.width;
}

int main()
{
	struct Rect rc;			//定义结构体变量
	printf("Please enter the length and width of the rectangle:\n");
	scanf("%f%f",&rc.length,&rc.width);			//获取用户输入的长和宽
	calculate(rc);				//调用calculate函数，计算矩形面积
	printf("The area of the rectangle is: %.2f.\n",rc.area);
	return 0;
}

Please enter the length and width of the rectangle:
4 5
The area of the rectangle is: 0.00.

struct Rect calculate(struct Rect rect)
{
	rect.area = rect.length * rect.width;
	return rect;			//返回修改后的结构体变量rect
}

rc = calculate(rc);

Please enter the length and width of the rectangle:
4 5
The area of the rectangle is: 20.00.

void calculate(struct Rect *pRect)
{
	pRect->area = pRect->length * pRect->width;
}

calculate(&rc);

Please enter the length and width of the rectangle:
4 5
The area of the rectangle is: 20.00.

struct Rect* calculate(struct Rect *pRect)
{
	pRect->area = pRect->length * pRect->width;
	return pRect;
}

rc = *calculate(&rc);

🍓结构体与字符串

struct Stu
{
	int num;			//学号
	char *name;			//姓名
};

struct Stu stu1 = {1,"Tom"};

stu1.name = "tom";

char str[20] = "Tom";
stu1.name = str;
*stu1.name = str;
printf("Name: %s\n",stu1.name);

Mane: tom

struct Stu stu2 = stu1;

strcpy(stu2.name,Jack);

printf("stu1 Name: %s\n",stu1.name);
printf("stu2 Name: %s\n",stu2.name);

stu1 Name: Jack
stu2 Name: Jack

#include <stdio.h>
#include <string.h>
struct Stu
{
	int num;			//学号
	char *name;			//姓名
};
int main()
{
	struct Stu stu1 = {1,"Tom"};
	char str1[20] = "Tom";
	stu1.name = str1;
	
	struct Stu stu2 = stu1;
	char str2[20];
	stu2.name = str2;

	strcpy(stu2.name,"Jack");

	printf("stu1 Name: %s\n",stu1.name);
	printf("stu2 Name: %s\n",stu2.name);
	return 0;
}