成员函数编程教程

1、第十九次作业下面是一个三角形类Triangle的定义：class Triangle public:Triangle(double a, double b, double c) int saveToFile(ostream &outFile); int loadFromFile(istream *inFile); x=a; y=b; z=c;private:Double x, y, z;(1) 实现成员函数saveToFile，将对象自身保存到文件中。(2) 实现成员函数loadFromFile，从文件中恢复对象。(3) 编写程序使用Triangle类，并实现如下功能： 将类Triang

2、le的多个对象保存到一个指定文件中； 能一次从指定文件中恢复多个对象。解：(1)(2)#if !defined _Triangle_H_#define _Triangle_H_#include<iostream>using namespace std;class Triangle public:Triangle(double a, double b, double c) void set(double a,double b,double c) int saveToFile(ostream &outFile); int loadFromFile(istream *inFile

3、); void print(void) cout<<x<<" "<<y<<" "<<z<<endl; x=a; y=b; z=c; x=a; y=b; z=c;private:;int Triangle:saveToFile(ostream &outFile) int Triangle:loadFromFile(istream *inFile) #endif#include"gong.h"#include<fstream>using names

4、pace std;int main()int reo,rei;fstream outFile("out.txt",ios:out);Triangle A(2,3,4); cout<<"Initial value:"<<endl; A.print(); reo=A.saveToFile(outFile); if(!(*inFile) *inFile>>x>>y>>z; if(*inFile).fail() return 0; return 0; else if(inFile->fail()

5、cout<<"Failure to open the file!"<<endl; return 0; if(!outFile) outFile<<x<<" "<<y<<" "<<z<<endl; if(outFile.fail() return 0; else if(outFile.bad() return 0; cout<<"Failure to open the file!"<<endl; r

6、eturn 0; double x, y, z; else return 1; else return 1; if(reo=0) cout<<"Saved to document the value of:n" A.print(); outFile.close(); A.set(1.9,2.1,2.5); cout<<"After re-setting the value:"<<endl; A.print(); fstream inFile("out.txt",ios:in); rei=A.load

7、FromFile(&inFile); if(rei=0) cout<<"Read from the file after the value:"<<endl; A.print(); inFile.close(); return 0; cout<<"Input error!"<<endl; exit(0); cout<<"Input error!"<<endl; exit(0);(3)#if !defined _Triangle_H_ #define _Tr

8、iangle_H_ #include<iostream>using namespace std; class Triangle public:Triangle() Triangle(double a, double b, double c) void set(double a,double b,double c) int saveToFile(ostream &outFile); x=a; y=b; z=c; x=a; y=b; z=c;int loadFromFile(istream *inFile); void print(void) cout<<x<

9、<" "<<y<<" "<<z<<endl;private:;int Triangle:saveToFile(ostream &outFile) int Triangle:loadFromFile(istream *inFile) #endif#include"gong.h"#include<fstream>using namespace std;const int N=5;int main()int i; if(!(*inFile) *inFile>&g

10、t;x>>y>>z; if(*inFile).fail() return 0; return 0; cout<<"Failure to open the file!"<<endl; return 0; if(!outFile) outFile<<x<<" "<<y<<" "<<z<<endl; if(outFile.fail() return 0; return 0; else if(outFile.bad() co

11、ut<<"Failure to open the file!"<<endl; return 0; double x, y, z; else return 1; else if(inFile->fail() else return 1;int reo,rei; Triangle aN; for(i=0;i<N;i+) ai.set(i,i*2,i*3); fstream outFile("out.txt",ios:out); for(i=0;i<N;i+) reo=ai.saveToFile(outFile); i

12、f(reo=0) cout<<"Saved to document the value of:"<<endl; for(i=0;i<N;i+) ai.print(); cout<<"Input error!"<<endl; exit(0); outFile.close(); for(i=0;i<N;i+) ai.set(i+1,i+2,i+3); cout<<"After re-setting the value:"<<endl; for(i=0;i<N;i+) ai.print(); fstream inFile("out.txt",ios:in); for(i=0;i<N;i+) cout<<"Read from the file after the value