C++学习笔记之结构体与类的区别

1、在C++中的， 结构体具有类的全部功能， 区别在于结构体成员默认为public, 而类的成员默认为private。

#include<iostream>
using namespace std;
class A //将class换成struct完全没问题。
{
public:
int get(){return i;}
void set(int x){ i=x; }
private:
int i;
};
int main()
{
A a;
a.set(100);
cout<<a.get()<<endl;
return 0;
}

//----------------------------------------------------------------------------------------------------------------

#include<iostream>
using namespace std;
void check(bool s);
struct people //将class换成struct完全没问题。
{
double weight;
double tall;
char*name;
char*native;
bool sex;
};

int main()
{
people Jack=
{
180.5,
175.8,
"Jack",
"杭州",
1
} ;
cout<<Jack.weight<<endl;
cout<<Jack.tall<<endl;
cout<<Jack.name<<endl;
cout<<Jack.native<<endl;
check(Jack.sex);
cout<<endl;
return 0;
}

void check(bool s){if (s==1)cout<<"男";else cout<<"女";}

-----------------------------------------------------------------------------------------------------------------

//struct与构造函数。
#include<iostream>
#include <string>
using namespace std;
void check(bool s);
struct people
{
people(double t_weight, double t_tall, string name, string native, bool t_sex);
double weight;
double tall;
string name;//
string native;//
bool sex;
};
void check(bool s){if (s==1)cout<<"男";else cout<<"女";}
int main()
{
people Jack
(
180.5,
175.8,
"Jack",
"杭州",
1
) ;
cout<<Jack.weight<<endl;
cout<<Jack.tall<<endl;
cout<<Jack.name<<endl;
cout<<Jack.native<<endl;
check(Jack.sex);
cout<<endl;
return 0;
}
people::people(double t_weight, double t_tall, string t_name, string t_native, bool t_sex)
{
weight = t_weight;
tall = t_tall;
name = t_name;
native = t_native;
sex = t_sex;
}

//-------------------------------------------------------------------------------------------------------------------------

//--------------------------------------------------------------------------
//struct是一种数据类型, 可以对其直接赋值， 但必须类型是一致的。
#include<iostream>
using namespace std;
struct people
{
double weight;
double tall;
};
int main()
{
people Jack = {140.5, 175.5};
people Mike = {120.6, 170.5};
Mike = Jack;
cout<<Jack.weight<<" "<<Jack.tall<<endl;
cout<<Mike.weight<<" "<<Mike.tall<<endl;
return 0;
}

//---------------------------------------------------------------------------------------------
//struct是一种数据类型, 可以将结构体传递给函数， 或者是返回结构体。
#include<iostream>
using namespace std;
struct time
{
int hour;
int minute;
};
const int perhour=60;
time sum(time t1, time t2);
void show(time t){cout<<t.hour<<":"<<t.minute<<endl;}
int main()
{
time one={8, 15};
time two={6, 55};
time day=sum(one , two);
cout<<"二天时间总计：";
show(day);
time day3={9, 35};
cout<<"三天时间总计：";
show(sum(day, day3));
return 0;
}
time sum(time t1, time t2)
{
time total;
total.minute=(t1.minute+t2.minute)%perhour;
total.hour=t1.hour+t2.hour+(t1.minute+t2.minute)%perhour;
return total;
}

//使用指针， 返回地址. 这样做的好处是由于返回的是地址， 就不需调用复制构造函数， 结省内存开销。
#include<iostream>
using namespace std;
struct time
{
int hour;
int minute;
};
const int perhour=60;
time *sum(time t1, time t2);
void show(time t){cout<<t.hour<<":"<<t.minute<<endl;}
int main()
{
time one={8, 15};
time two={6, 55};
time *day=sum(one , two);
cout<<"二天时间总计：";
show(*day);
time day3={9, 35};
cout<<"三天时间总计：";
time *p=sum(*day, day3);
show(*p);
return 0;
}
time *sum(time t1, time t2)
{
time *total = new time;
total->minute=(t1.minute+t2.minute)%perhour;
total->hour=t1.hour+t2.hour+(t1.minute+t2.minute)%perhour;
return total;
}

//--------------------------------------------------------------------------------
//结构体与String类
//多个字符串传递给函数。
#include<iostream>
#include <string>
using namespace std;
void show(string str[], int count);
int main()
{
const int length = 5;
string str1[length];
for(int i=0; i<length; i++)
{
cout<<i+1<<":";
cin>>str1[i];
}
show(str1, length);
return 0;
}
void show(string str[], int count)
{
for (int i=0; i<count; i++)
{
cout<<i+1<<":"<<str[i]<<endl;
}
}