C++怎么进行文件读写操作_C++ IO流编程与fstream使用指南

#include <fstream>
#include <iostream>
using namespace std;
<p>int main() {
ofstream outFile("data.txt");  // 创建输出文件流
if (outFile.is_open()) {
outFile << "Hello, C++ File!" << endl;
outFile << 123 << " " << 3.14 << endl;
outFile.close();
}</p><pre class='brush:php;toolbar:false;'>ifstream inFile("data.txt");   // 创建输入文件流
string line;
if (inFile.is_open()) {
    while (getline(inFile, line)) {
        cout << line << endl;
    }
    inFile.close();
}
return 0;

fstream file("log.txt", ios::out | ios::app); // 追加写入
fstream binFile("data.bin", ios::out | ios::binary); // 二进制写

struct Person {
    char name[20];
    int age;
};
<p>Person p = {"Tom", 25};
ofstream binOut("person.dat", ios::binary);
binOut.write(reinterpret_cast<char*>(&p), sizeof(p));
binOut.close();</p>

ifstream binIn("person.dat", ios::binary);
Person p2;
if (binIn.read(reinterpret_cast<char*>(&p2), sizeof(p2))) {
    cout << "Name: " << p2.name << ", Age: " << p2.age << endl;
}
binIn.close();

ifstream file("missing.txt");
if (!file) {
    cerr << "无法打开文件！" << endl;
    return -1;
}