基础之基础之最后一节-结构体
1.结构体的定义
结构体相对于自定义的一种新的变量类型。
四种定义方式，推荐第一种；第四种适合大量定义，也适合查找；
cpp
#include <iostream>
using namespace std;
#include <string.h>
struct Student
{
string name;
int age;
float score;
}s3;
void prinf(Student s)
{
cout << s.name << " | " << s.age << " | " << s.score << endl;
}
int main()
{
Student s1;
s1.name = "niuniu";
s1.age = 18;
s1.score = 96;
prinf(s1);
Student s2 = { "zhangsan", 92, 30 };
prinf(s2);
s3.name = "lisi";
s3.age = 13;
s3.score = 31;
prinf(s3);
//shuzu
Student arr[3] = {
{"zhangsan", 31,55},
{"lisi", 41, 42},
{"wangwu", 32,44}
};
for (int i = 0; i < 3; ++i)
{
prinf(arr[i]);
};
return 0;
}2.结构体指针
和其他类型的指针一致；需要注意的是，如果s是结构体的指针，不仅可以使用(*s).name还可以使用s->name访问结构体的属性；
cpp
#include <iostream>
using namespace std;
#include <string.h>
struct Student
{
string name;
int age;
float score;
}s3;
void prinf(Student* s)
{
cout << s->name << " | " << s->age << " | " << s->score << endl;
}
int main()
{
Student s1;
s1.name = "niuniu";
s1.age = 18;
s1.score = 96;
prinf(&s1);
Student s2 = { "zhangsan", 92, 30 };
prinf(&s2);
s3.name = "lisi";
s3.age = 13;
s3.score = 31;
prinf(&s3);
//shuzu
Student arr[3] = {
{"zhangsan", 31,55},
{"lisi", 41, 42},
{"wangwu", 32,44}
};
for (int i = 0; i < 3; ++i)
{
prinf(&arr[i]);
};
return 0;
}3.结构体嵌套结构体
类似于函数中包含函数；
cpp
#include <iostream>
using namespace std;
#include <string.h>
struct teacher
{
int id;
string name;
int age;
student std;
};
struct student
{
string name;
int age;
int score;
};结果报错，因为需要把student放在前面！！！
4.案例
4.1给三国英雄排序；使用结构体，指针
cpp
#include <iostream>
#include <string.h>
using namespace std;
struct hero
{
string name;
int age;
string gender;
};
void prf(hero arr[5])
{
for (int i = 0; i < 5; i++)
{
cout << arr[i].name << " | " << arr[i].age << " | " << arr[i].gender << endl;
}
}
void sort(hero arr[5], const int nums)
{
for (int i = 0; i < nums; i++)
{
int counts = nums;
for (int j = 0; j < nums - i - 1; j++)
{
if (arr[j].age > arr[j + 1].age)
{
hero tmp = arr[j];
arr[j] = arr[j + 1];
arr[j + 1] = tmp;
counts--;
}
}
}
}
int main()
{
hero arr[5] = {
{"liubei",22,"nan"},
{"guanyu", 22, "nan"},
{"zhangfei", 20, "nan"},
{"zhaoyun", 21, "nan"},
{"diaochan", 19, "nv"}
};
sort(arr, 5);
prf(arr);
return 0;
}4.2通讯录案例
cpp
#include <iostream>
#include <string.h>
#define MAX 1000
using namespace std;
struct People
{
string name;
int gender;
int age;
long phone;
string address;
};
struct AddressBook
{
People addressbook[MAX];
int nums;
};
void init()
{
cout << "*****************" << endl;
cout << "please choice one" << endl;
cout << "1. add contact" << endl;
cout << "2. display contact" << endl;
cout << "3. delete contact" << endl;
cout << "4. search contact" << endl;
cout << "5. revise contact" << endl;
cout << "6. delete all contact" << endl;
cout << "7. out system" << endl;
cout << "*****************" << endl;
}
void add(AddressBook* abs)
{
string name;
int gender;
int age;
long phone;
string address;
cout << "please input contact name" << endl;
cin >> name;
cout << "please input contact gender (1: nan; 2: nv" << endl;
cin >> gender;
cout << "please input contact age" << endl;
cin >> age;
cout << "please input contact phone" << endl;
cin >> phone;
cout << "please input contact address" << endl;
cin >> address;
abs->addressbook[abs->nums].name = name;
abs->addressbook[abs->nums].age = age;
abs->addressbook[abs->nums].gender = gender;
abs->addressbook[abs->nums].phone = phone;
abs->addressbook[abs->nums].address = address;
abs->nums++;
}
void display(AddressBook* abs)
{
for (int i = 0; i < abs->nums; i++)
{
cout << "name : " << abs->addressbook[i].name << "\t";
cout << "gender : " << abs->addressbook[i].gender << "\t";
cout << "age : " << abs->addressbook[i].age << "\t";
cout << "phone : " << abs->addressbook[i].phone << "\t";
cout << "address : " << abs->addressbook[i].address << "\t";
cout << endl;
};
}
int Search(AddressBook* abs, int* p_c)
{
string name;
int idx = 0;
cout << "please input contact name" << endl;
cin >> name;
for (int i = 0; i < abs->nums; i++)
{
if (abs->addressbook[i].name == name)
{
if (*p_c != 4)
{
return i;
}
cout << "name : " << abs->addressbook[i].name << "\t";
cout << "gender : " << abs->addressbook[i].gender << "\t";
cout << "age : " << abs->addressbook[i].age << "\t";
cout << "phone : " << abs->addressbook[i].phone << "\t";
cout << "address : " << abs->addressbook[i].address << "\t";
cout << endl;
}
}
}
void Delete(AddressBook* abs, int* p_c)
{
int idx = Search(abs, p_c);
for (int i = idx; i < abs->nums; i++)
{
abs->addressbook[i] = abs->addressbook[i + 1];
}
abs->nums--;
}
void Revise(AddressBook* abs, int* p_c)
{
Delete(abs, p_c);
add(abs);
}
void DelAll(AddressBook* abs)
{
abs->nums = 0;
}
int main()
{
int choice = 0;
AddressBook book;
book.nums = 0;
// init
book.addressbook[book.nums].name = "aaa";
book.addressbook[book.nums].age = 13;
book.addressbook[book.nums].gender = 1;
book.addressbook[book.nums].phone = 10010;
book.addressbook[book.nums].address = "dalian";
book.nums++;
book.addressbook[book.nums].name = "ooo";
book.addressbook[book.nums].age = 52;
book.addressbook[book.nums].gender = 2;
book.addressbook[book.nums].phone = 10086;
book.addressbook[book.nums].address = "suzhou";
book.nums++;
// end
while (1)
{
init();
cin >> choice;
// add, display, delete, search, revise, delete all, out
switch (choice)
{
case(1):
{
add(&book);
break;
};
case(2):
{
display(&book);
break;
};
case(3):
{
Delete(&book, &choice);
break;
};
case(4):
{
Search(&book, &choice);
break;
};
case(5):
{
Revise(&book, &choice);
break;
};
case(6):
{
DelAll(&book);
break;
};
default:
break;
}
if (choice == 7)
{
break;
};
system("pause");
system("cls");
}
}总结一下：
1.对于python来说，数组传入函数时，相当于传入c++指针，因为函数中改变数组中的值，外部的数组也会改变；所以不想改变的时候，需要使用deep.copy。
2.对于c++来说，不仅数组传入相对于指针，对于整型、实型及结构体，只要使用&a，把a的指针传入函数，在函数中修改后，外部的值也会改变。
3.对于c++的数组来说，就算不使用*p，arr本身也是地址。所以在函数中对于传入的arr来说，不需要使用指针，也能干指针的活；