【c基礎練習】結構體
阿新 • • 發佈：2019-01-02
1.結構體成員的使用
#define _CRT_SECURE_NO_WARNINGS #include<stdio.h> #include<string.h> #include<stdlib.h> struct Person { char name[64]; int age; }; int main() { //棧上分配空間 struct Person p1; strcpy(p1.name, "john"); p1.age = 30; printf("Name:%s Age:%d\n", p1.name, p1.age); //在堆區分配空間 struct Person* p2 = (struct Person*)malloc(sizeof(struct Person)); strcpy(p2->name, "tom"); p2->age = 22; printf("Name:%s Age:%d\n", p2->name, p2->age); system("pause"); return EXIT_SUCCESS; }
2.結構體賦值
#define _CRT_SECURE_NO_WARNINGS #include<stdio.h> #include<string.h> #include<stdlib.h> struct Person { char name[20]; int age; }; int main() { struct Person p1 = { "John", 30 }; struct Person p2 = { "tom", 22 }; printf("Name:%s Age:%d\n", p1.name, p1.age); printf("Name:%s Age:%d\n", p2.name, p2.age); p1 = p2; printf("Name:%s Age:%d\n", p1.name, p1.age); printf("Name:%s Age:%d\n", p2.name, p2.age); system("pause"); return EXIT_SUCCESS; }
3.結構體陣列
#define _CRT_SECURE_NO_WARNINGS #include<stdio.h> #include<string.h> #include<stdlib.h> struct Person { char name[20]; int age; }; int main() { //在棧上分配空間 struct Person p1[3] = { { "john", 30 }, { "tom", 22 }, { "jerry",23 } }; struct Person p2[3] = { "john", 30, "tom", 22, "jerry", 23 }; for (int i = 0; i < 3; i++) { printf("Name:%s,Age:%d\n", p1[i].name, p1[i].age); } printf("________________________________\n"); for (int i = 0; i < 3; i++) { printf("Name:%s,Age:%d\n", p2[i].name, p2[i].age); } printf("________________________________\n"); //在堆上分配空間 struct Person* p3 = (struct Person*)malloc(sizeof(struct Person) * 3); for (int i = 0; i < 3; i++) { sprintf((p3+i)->name, "Name:%d", i + 1); p3[i].age = 20 + i; } for (int i = 0; i < 3; i++) { printf("Name:%s,Age:%d\n", p3[i].name, p3[i].age); } system("pause"); return EXIT_SUCCESS; }
4.結構體巢狀一級指標
#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
struct Person
{
char* name;
int age;
};
void allocate_mem(struct Person** p)
{
if (NULL == p)
{
return;
}
struct Person* temp =(struct Person*)malloc(sizeof(struct Person));
if (NULL == temp)
{
return;
}
temp->age = 100;
//給name指標分配記憶體
temp->name = (char*)malloc(sizeof(char)* 64);
strcpy(temp->name, "tom");
*p= temp;
}
void printf_Person(struct Person* p)
{
printf("Name:%s,Age:%d\n", p->name, p->age);
}
void free_mem(struct Person** p)
{
if (NULL == p)
{
return;
}
struct Person* temp = *p;
if (NULL == temp->name)
{
free(temp->name);
temp->name = NULL;
}
free(temp);
}
int main()
{
struct Person* p=NULL;
allocate_mem05(&p);
printf_Person05(p);
free_mem05(&p);
system("pause");
return EXIT_SUCCESS;
}5.結構體巢狀二級指標
#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
//一個老師有n個學生
typedef struct _TEACHER
{
char name[64];
char** students;
}Teacher;
void create_teacher(const Teacher** teacher, int n, int m)
{
if (teacher == NULL)
{
return;
}
//建立老師陣列
Teacher* temp_teacher = (Teacher*)malloc(sizeof(Teacher)*n);
if (NULL==temp_teacher)
{
return;
}
//給每個老師分配學生
int num = 0;
for (int i = 0; i < n; i++)
{
sprintf(temp_teacher[i].name, "老師_%d", i + 1);
temp_teacher[i].students = (char**)malloc(sizeof(char*)*m);
for (int j = 0; j < m; j++)
{
temp_teacher[i].students[j] = (char*)malloc(64);
sprintf(temp_teacher[i].students[j], "學生_%d", num + 1);
num++;
}
}
*teacher = temp_teacher;
}
void print_teacher(const Teacher* teacher, int n, int m)
{
for (int i = 0; i < n; i++)
{
printf("%s\n", teacher[i].name);
for (int j = 0; j < m; j++)
{
printf(" %s", teacher[i].students[j]);
}
printf("\n");
}
}
void free_mem(const Teacher** teacher, int n, int m)
{
if (NULL==teacher)
{
return;
}
Teacher* temp_teacher = *teacher;
for (int i = 0; i < n; i++)
{
for (int j = 0; j < m; j++)
{
free(temp_teacher[i].students[j]);
temp_teacher[i].students[j]=NULL;
}
free(temp_teacher[i].students);
temp_teacher[i].students = NULL;
}
free(temp_teacher);
temp_teacher = NULL;
}
int main()
{
Teacher* p=NULL;
create_teacher06(&p, 2, 3);
print_teacher06(p, 2, 3);
free_mem06(&p, 2, 3);
system("pause");
return EXIT_SUCCESS;
}習題：
//01 寫一個程式滿足一下要求：
//a.外部定義一個name結構模板，它含有2個成員:一個字串用於存放名字，另一個字串用於存放姓氏。
//b.外部定義一個student結構模板，它含有3個成員：一個name結構，一個存放3個浮點數分數的grade陣列，以及
//一個存放這3個分數的平均分的變數。
//c.在main函式中宣告一個具有CSIZE(CSIZE = 4)個student結構的陣列，並隨意初始化這些結構體的名字部分。使用
//函式來執行d、e、f以及g部分所描述的任務。
//d.請求使用者輸入學生的姓名和分數，以互動地獲得每個學生的成績。將分數存放到相應結構的grade陣列成員中。
//您可以自主選擇在main或者一個函式中實現這個迴圈。
//e.為這個結構計算平均分，並把這個值賦給適合的成員。
//f.輸出每個結構中的資訊。
//g.輸出結構的每個數值成員的班級平均分。
#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#define CSIZE 4
struct Name
{
char FristName[10];
char EndName[20];
};
typedef struct Student
{
struct Name n;
float Grade[3];
float Average;
}stu;
//d函式 ： 錄入學生資訊，求算平均分
void fun_in(struct Student *p, int num)
{
for (int i = 0; i < num; i++)
{
printf("請輸入學生姓名\n");
scanf("%s%s", &p[i].n.FristName, &p[i].n.EndName);
printf("請輸入成績\n");
scanf("%f%f%f", &p[i].Grade[0], &p[i].Grade[1], &p[i].Grade[2]);
p[i].Average = (p[i].Grade[0] + p[i].Grade[1] + p[i].Grade[2]) / 3;
}
}
void fun_out(struct Student *p, int num)
{
for (int i = 0; i <= num; i++)
{
printf("學生姓名:%s%s\n", p[i].n.FristName, p[i].n.EndName);
printf("成績%f\n", p[i].Average);
}
}
int main()
{
stu p[CSIZE];
fun_in(p,CSIZE);
fun_out(p, CSIZE);
system("pause");
return EXIT_SUCCESS;
}