c++ 读写文件

image.png

#include <iostream>
#include <fstream>
using namespace std;

int main() {
    
    //读
    //ifstream inFile;
    //inFile.open("/Users/mouos/Desktop/data.txt", ios::in)
    
    //ifstream inFile("/Users/mouos/Desktop/data.txt", ios::in);
    ifstream inFile("/Users/mouos/Desktop/data.txt");
    if (inFile) {
        cout<<"打开成功"<<endl;
        inFile.close();
    } else cout<<"打开失败"<<endl;
    
    //写
    //ofstream outFile;
    //outFile.open("/Users/mouos/Desktop/data.txt", ios::out | ios::binary);
    
    //ofstream outFile("/Users/mouos/Desktop/data.txt", ios::out | ios::binary);
    ofstream outFile("/Users/mouos/Desktop/data.txt", ios::out);
    if (outFile) {
        cout<<"打开成功"<<endl;
        inFile.close();
    } else cout<<"打开失败"<<endl;
    
    //读写
    fstream file("/Users/mouos/Desktop/data.txt", ios::out | ios::in);
    if (outFile) {
        cout<<"打开成功"<<endl;
        inFile.close();
    } else cout<<"打开失败"<<endl;
    
    return 0;
} 

写文件文本

#include <iostream>
#include <fstream>
using namespace std;

int main() {
    
    char id[11], name[21];
    int score;
    ofstream outFile;
    outFile.open("/Users/mouos/Desktop/data.txt");
    if (!outFile) {
        cout<<"创建文件失败"<<endl;
        return 0;
    }
    
    cout<<"输入：学号 姓名 成绩（ctrl+Z结束输入，mac下control+D结束输入）"<<endl;
    while (cin>>id>>name>>score) {
        outFile<<id<<" "<<name<<" "<<score<<endl;
    }
    outFile.close();
    
    return 0;
} 

读文件文本

#include <iostream>
#include <iomanip>
#include <fstream>
using namespace std;

int main() {
    
    char id[11], name[21];
    int score;
    ifstream inFile;
    inFile.open("/Users/mouos/Desktop/data.txt");
    if (!inFile) {
        cout<<"打开文件失败"<<endl;
        return 0;
    }
    cout<<"学号 姓名 成绩\n";
    while (inFile>>id>>name>>score) {
        cout<<left<<setw(10)<<id<<" "<<setw(10)<<name<<" "<<setw(10)<<right<<score<<endl;
    }
    inFile.close();
    
    return 0;
} 

读写二进制文件

#include <iostream>
#include <fstream>
using namespace std;

class Student {
  
public:
    char id[11];
    char name[21];
    int score;
};

int main() {
    
    Student stu;
    ofstream outFile("/Users/mouos/Desktop/data.dat", ios::out | ios::binary);
    if (!outFile) {
        cout<<"创建文件失败"<<endl;
        return 0;
    }
    
    while (cin>>stu.id>>stu.name>>stu.score) {
        outFile.write((char*)&stu, sizeof(stu));
    }
    outFile.close();
    
    return 0;
}