類,數據成員(一般爲私有private),成員函數(一般爲公有public)
一般的程序:若干對象+對象間的消息傳遞
#include <iostream>
#include<cstring>
using namespace std;
class Student
{
public:
void setdata(int n,string p,char s);
void display();
private:
int num;
string name;
char sex;
};
void Student::setdata(int n,string p,char s)
{
num=n;
name=p;
sex=s;
}
void Student::display()
{
cout<<"num:"<<num<<endl;
cout<<"name:"<<name<<endl;
cout<<"sex:"<<sex<<endl;
}
int main()
{
Student stud1,stud2;
stud1.setdata(1,"zhang",'F');
stud2.setdata(2,"Li",'M');
stud1.display();
stud2.display();
return 0;
}
學生信息及成績處理
構造三角形類,輸入三邊長,輸出周長、面積
/*
*copyright(c) 2020,HH
*All rights reserved.
*作 者:HH
*完成日期:2020年1月10日
*版本號:v1.0
*
*問題描述:輸入三角形的三個邊長,若能組成三角形,則輸出此三角形的周長,面積;
*輸入描述:三角形三邊長 a b c;
*程序輸出:三角形 周長perimeter 面積Area;
*備註:
*/
#include <iostream>
#include<cstring>
#include<Cmath>
#include<cstdlib>
using namespace std;
class Triangle
{
public:
void setABC(double x,double y,double z);
double perimeter();
double area();
private:
double a,b,c;
};
void Triangle::setABC(double x,double y,double z)
{
if(x+y>z&&x+z>y&&y+z>x)
{
a=x;
b=y;
c=z;
}
else
{
cout<<"Cann't zucheng SanJiaoxXing"<<endl;
exit(0);
}
}
double Triangle::perimeter()
{
return a+b+c;
}
double Triangle::area()
{
double p=(a+b+c)/2;
return sqrt(p*(p-a)*(p-b)*(p-c));
}
int main()
{
Triangle tri1;
double x,y,z;
cin>>x>>y>>z;
tri1.setABC(x,y,z);
cout<<"Perimeter:"<<tri1.perimeter()<<'\n'<<"Area is:"<<tri1.area()<<endl;
return 0;
}