C++中std::getline()函数读取整行文本的用法详解

operator>>

std::getline(std::istream& is, std::string& str, char delim);

std::getline(std::istream& is, std::string& str);

#include <iostream>
#include <string>
int main() {
    std::string line;
    std::cout << "请输入一行文字：";
    std::getline(std::cin, line);
    std::cout << "你输入的是：" << line << std::endl;
    return 0;
}

std::cin >> variable

operator>>

int age;
std::string name;
std::cout << "输入年龄：";
std::cin >> age;
std::cout << "输入姓名：";
std::cin.ignore(); // 忽略上一个输入留下的换行符
std::getline(std::cin, name);

std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');

std::ifstream

#include <iostream>
#include <fstream>
#include <string>
int main() {
    std::ifstream file("data.txt");
    std::string line;
    while (std::getline(file, line)) {
        std::cout << line << std::endl;
    }
    file.close();
    return 0;
}

data.txt

std::getline(file, line)

std::string field;
std::istringstream iss("apple,banana,orange");
while (std::getline(iss, field, ',')) {
    std::cout << field << std::endl;
}