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@rnatlance203 在 C++中流重载使用方法 中说:
还有个问题,就是如果私有或者受保护成员是字符串或者数组的话怎么整
(史前大坑)
我发现我就是个人才,就算挖坑都不会把自己坑到
class blu {
protected:
char s[100];
char c[100];
char p;
public:
blu() {
strcpy(s, "fsk");
strcpy(c, "fkb");
p = 'z';
}
~blu() {
}
friend istream & operator>>(istream & in, blu &cu) {
in >> cu.s >> cu.c >> cu.p;
return in;
}
friend ostream & operator<<(ostream & out, blu &cu) {
out << cu.s << '\t' << cu.c << '\t' << cu.p;
return out;
}
};
这不是跟上面的整型变量一样了吗 成员函数都不用写了,爽死
@rnatlance203 在 C++中流重载使用方法 中说:
还可以拓展一下 虽然用了臭名昭著的goto,(但是)对于这种规模的东西也没必要上那些高端操作
其实就是偷懒
codelist_2.cpp// codelist_2.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。 // #include<iostream> #include<iomanip> #include<fstream> #include<string> #include<stdlib.h> #include<set> using namespace std; class type { protected: int str1; int str2; int str3; public: type() { str1 = 0, str2 = 0, str3 = 0; } ~type() {}; friend istream & operator>>(istream & in, type &cu ) { in >> cu.str1 >> cu.str2 >> cu.str3; return in; } friend ostream & operator<<(ostream & out, const type &st) { out << st.str1 << st.str2 << st.str3 << endl; return out; } int getstr1() { return str1; } int getstr2() { return str2; } int getstr3() { return str3; } }; void readFile() { type type0; ifstream fkb("fkb.txt"); fkb >> type0; cout << type0 << endl; fkb.close(); } void writeFile() { type type0; ofstream fkb("fkb.txt"); cin >> type0; fkb << type0 << endl; fkb.close(); } int main() { int choice; MAIN: { system("cls"); cout << "1=read/2=write/0=exit" << endl; cin >> choice; if (choice == 1) goto READ; else { if (choice == 2) goto WRITE; else return 0; } } READ: { readFile(); system("pause"); goto MAIN; } WRITE:{ writeFile(); system("pause"); goto MAIN; } return 0; }
我是不知道我拓展了个什么玩意,我只知道大半夜很容易出错
函数void readFile()
只能读第一行而且会把所有数据连在一起,一眼就能看出;
函数void writeFile()
写入的时候会把所有数据都连在一起,再读取的话就gg;
修复的方法也很简单
//在class type里的插入流重载中--------------------
friend ostream & operator<<(ostream & out, blu &cu) {
out << cu.s << '\t' << cu.c << '\t' << cu.p;
return out;
}
//-----------------------------------------------
void readFile() {
char str[100];
ifstream fkb("fkb.txt");
while (fkb.getline(str, 100)) {
cout << str << endl;
}
}
void writeFile() {
type type0;
ofstream fkb("fkb.txt", ios::app);
cin >> type0;
fkb << type0 << endl;
fkb.close();
}
还可以拓展一下 虽然用了臭名昭著的goto,(但是)对于这种规模的东西也没必要上那些高端操作其实就是偷懒
codelist_2.cpp
// codelist_2.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//
#include<iostream>
#include<iomanip>
#include<fstream>
#include<string>
#include<stdlib.h>
#include<set>
using namespace std;
class type
{
protected:
int str1;
int str2;
int str3;
public:
type() {
str1 = 0, str2 = 0, str3 = 0;
}
~type() {};
friend istream & operator>>(istream & in, type &cu ) {
in >> cu.str1 >> cu.str2 >> cu.str3;
return in;
}
friend ostream & operator<<(ostream & out, const type &st) {
out << st.str1 << st.str2 << st.str3 << endl;
return out;
}
int getstr1() {
return str1;
}
int getstr2() {
return str2;
}
int getstr3() {
return str3;
}
};
void readFile() {
type type0;
ifstream fkb("fkb.txt");
fkb >> type0;
cout << type0 << endl;
fkb.close();
}
void writeFile() {
type type0;
ofstream fkb("fkb.txt");
cin >> type0;
fkb << type0 << endl;
fkb.close();
}
int main() {
int choice;
MAIN: {
system("cls");
cout << "1=read/2=write/0=exit" << endl;
cin >> choice;
if (choice == 1) goto READ;
else
{
if (choice == 2) goto WRITE;
else return 0;
}
}
READ: {
readFile();
system("pause");
goto MAIN;
}
WRITE:{
writeFile();
system("pause");
goto MAIN;
}
return 0;
}
那么有什么实用价值呢
如下
codelist_1.cpp
// codelist_1.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//
#include<iostream>
#include<iomanip>
#include<fstream>
#include<string>
#include<stdlib.h>
#include<set>
using namespace std;
class type
{
private:
int str1;
int str2;
int str3;
public:
type() {
str1 = 0, str2 = 0, str3 = 0;
}
~type() {};
friend istream & operator>>(istream & in, type &cu ) {
in >> cu.str1 >> cu.str2 >> cu.str3;
return in;
}
friend ostream & operator<<(ostream & out, const type &st) {
out << st.str1 << st.str2 << st.str3 << endl;
return out;
}
int getstr1() {
return str1;
}
int getstr2() {
return str2;
}
int getstr3() {
return str3;
}
};
int main() {
type type0;
ofstream fkb("fkb.txt");
cin >> type0;
fkb << type0.getstr1() << type0.getstr2() << type0.getstr3() << endl;
return 0;
}
实际作用大概是省下了从键盘cin到文件整个过程的文字量,而且这份代码是示例,class只有3个私有成员,如果是大型工程,一个一个cin写那必然是要出人命的
codelist_0.cpp
#include<iostream>
#include<iomanip>
#include<fstream>
#include<string>
#include<stdlib.h>
#include<set>
using namespace std;
class type
{
private:
int str1;
int str2;
int str3;
public:
type() {
str1 = 0, str2 = 0, str3 = 0;
}
~type() {};
friend istream & operator>>(istream & in, type &cu ) {
in >> cu.str1 >> cu.str2 >> cu.str3;
return in;
}
friend ostream & operator<<(ostream & out, const type &st) {
out << st.str1 << st.str2 << st.str3 << endl;
return out;
}
};
int main() {
type type0;
cin >> type0;
cout << type0;
}
这应该是最简单的重载流示例了