指向结构的指针包含整个结构的添加。
它用于创建复杂的数据结构,如链表、树、图等。
可以使用称为箭头运算符 ( -> ) 的特殊运算符来访问结构的成员。
声明
以下是 C 编程中指向结构的指针的声明
struct tagname *ptr;
例如:struct student *s;
访问
下面将介绍如何访问指向结构的指针。
Ptr-> membername;
例如 − s->sno、s->sname、s->marks;
例
下面是一个 C 程序,它解释了 C 编程中结构的动态内存分配
#include <stdio.h>
#include <stdlib.h>
struct person {
int age;
float weight;
char name[30];
};
int main(){
struct person *ptr;
int i, n;
printf("Enter the number of persons: ");
scanf("%d", &n);
// allocating memory for n numbers of struct person
ptr = (struct person*) malloc(n * sizeof(struct person));
for(i = 0; i < n; ++i){
printf("Enter name and age respectively: ");
// To access members of 1st struct person,
// ptr->name and ptr->age is used
// To access members of 2nd struct person,
// (ptr+1)->name and (ptr+1)->age is used
scanf("%s %d", (ptr+i)->name, &(ptr+i)->age);
}
printf("Displaying Information:
");
for(i = 0; i < n; ++i)
printf("Name: %s\tAge: %d
", (ptr+i)->name, (ptr+i)->age);
return 0;
}
输出
当执行上述程序时,它会产生以下结果
Enter the number of persons: 1
Enter name and age respectively: bhanu 24
Displaying Information:
Name: bhanu Age: 24
示例 2
考虑另一个关于指针和结构的例子,其中给出了一个用于演示指针和结构的 C 程序。
扫描二维码关注公众号,回复:
17487853 查看本文章
#include<stdio.h>
//Declaring outer and inter structures//
struct Manager{
char Name[15];
int Age;
char Gender;
float Level;
char Role[50];
char temp;
}m[20];
void main(){
//Declaring variable for For loop and pointer variable//
int i;
struct Manager *p;
//Defining Pointer//
p=&m;
//Reading User I/p//
for (i=1;i<3;i++){//Declaring function to accept 2 manager's data//
printf("Enter the Name of manager %d : ",i);
gets(p->Name);
printf("Enter the Age of manager %d : ",i);
scanf("%d",&p->Age);
scanf("%c",&p->temp);//Clearing Buffer//
printf("Enter the Gender of manager %d : ",i);
scanf("%c",&p->Gender);
//scanf("%c",&p->temp);//Clearing Buffer//
printf("Enter the level of manager %d : ",i);
scanf("%f",&p->Level);
scanf("%c",&p->temp);//Clearing Buffer//
printf("Enter the role of manager %d : ",i);
gets(p->Role);
p++;
}
//Defining Pointer one more time to print output//
p=&m;
//Printing O/p//
for (i=1;i<3;i++){
printf("The Name of Manager %d is : %s
",i,p->Name);
printf("The Age of Manager %d is : %d
",i,p->Age);
printf("The Gender of Manager %d is : %c
",i,p->Gender);
printf("The Level of Manager %d is : %f
",i,p->Level);
printf("The Role of Manager %d is : %s
",i,p->Role);
p++;
}
}
输出
当执行上述程序时,它会产生以下结果
Enter the Name of manager 1 : Hari
Enter the Age of manager 1 : 55
Enter the Gender of manager 1 : M
Enter the level of manager 1 : 2
Enter the role of manager 1 : Senior
Enter the Name of manager 2 : Bob
Enter the Age of manager 2 : 60
Enter the Gender of manager 2 : M
Enter the level of manager 2 : 1
Enter the role of manager 2 : CEO
The Name of Manager 1 is : Hari
The Age of Manager 1 is : 55
The Gender of Manager 1 is : M
The Level of Manager 1 is : 2.000000
The Role of Manager 1 is : Senior
The Name of Manager 2 is : Bob
The Age of Manager 2 is : 60
The Gender of Manager 2 is : M
The Level of Manager 2 is : 1.000000
The Role of Manager 2 is : CEO