什么是C语言中的嵌套结构？
结构内的结构（或）嵌套结构
另一个结构内部的结构称为嵌套结构。
考虑以下示例，
struct emp{
int eno;
char ename[30];
float sal;
float da;
float hra;
float ea;
}e;津贴中的所有项目都可以组合在一起，并在如下所示的子结构中声明。
stuct emp{
int eno;
char ename[30];
float sal;
struct allowance{
float da;
float hra;
float ea;
}a;
}e;嵌套结构中最内部的成员可以通过使用点运算符使用该成员更改所有相关的结构变量（从最外部到最内部）来访问。
示例
以下程序演示嵌套结构（结构内的结构）-
示例
#include<stdio.h>
//Declaring outer and inter structures//
struct Person//Main Structure//{
char Name[500];
int Age;
char Gender;
char temp;//To clear buffer//
struct Address//Nested Structure//{
char Apartment[500];
char Street[500];
char City[100];
char State[100];
int Zipcode;
}a[20];//Nested Structure Variable//
}p[20];//Main Structure Variable//
void main(){
//Declaring variable for For loop//
int i;
//Reading User I/p//
for (i=1;i<3;i++)//Declaring function to accept 2 people's data//{
printf("Enter the Name of person %d : ",i);
gets(p[i].Name);
printf("Enter the Age of person %d : ",i);
scanf("%d",&p[i].Age);
scanf("%c",&p[i].temp);//Clearing Buffer//
printf("Enter the Gender of person %d : ",i);
scanf("%c",&p[i].Gender);
scanf("%c",&p[i].temp);//Clearing Buffer//
printf("Enter the City of person %d : ",i);
gets(p[i].a[i].City);
printf("Enter the State of person %d : ",i);
gets(p[i].a[i].State);
printf("Enter the Zip Code of person %d : ",i);
scanf("%d",&p[i].a[i].Zipcode);
scanf("%c",&p[i].temp);//Clearing Buffer//
}
//Printing O/p//
for (i=1;i<3;i++){
printf("The Name of person %d is : %s\n",i,p[i].Name);
printf("The Age of person %d is : %d\n",i,p[i].Age);
printf("The Gender of person %d is : %c\n",i,p[i].Gender);
printf("The City of person %d is : %s\n",i,p[i].a[i].City);
printf("The State of person %d is : %s\n",i,p[i].a[i].State);
printf("The Zip code of person %d is : %d\n",i,p[i].a[i].Zipcode);
}
}输出结果Enter the Name of person 1 : Enter the Age of person 1 : Enter the Gender of person 1 : Enter the City of person 1 : Enter the State of person 1 : Enter the Zip Code of person 1 : Enter the Name of person 2 : Enter the Age of person 2 : Enter the Gender of person 2 : Enter the City of person 2 : Enter the State of person 2 : Enter the Zip Code of person 2 : The Name of person 1 is : The Age of person 1 is : 0 The Gender of person 1 is : The City of person 1 is : The State of person 1 is : The Zip code of person 1 is : 0 The Name of person 2 is : The Age of person 2 is : 0 The Gender of person 2 is : The City of person 2 is : The State of person 2 is : The Zip code of person 2 is : 0