C++中string和stringstream怎么使用

在C++中，可以使用string和stringstream来处理字符串。

1. 使用string类来创建和操作字符串：

#include <iostream> #include <string>  int main() {     std::string str = "Hello, World!";      // 获取字符串长度     std::cout << "Length: " << str.length() << std::endl;      // 获取子字符串     std::string subStr = str.substr(0, 5);     std::cout << "Substring: " << subStr << std::endl;      // 连接字符串     std::string concatStr = str + " Welcome!";     std::cout << "Concatenated string: " << concatStr << std::endl;      // 查找字符串     std::size_t found = str.find("World");     if (found != std::string::npos) {         std::cout << "Found at index: " << found << std::endl;     } else {         std::cout << "Not found" << std::endl;     }      return 0; } 

2. 使用stringstream类来处理字符串流：

#include <iostream> #include <sstream>  int main() {     std::string str = "42 3.14 Hello";      std::istringstream iss(str); // 从字符串创建输入流     int num;     float fNum;     std::string word;      // 从流中提取数据     iss >> num >> fNum >> word;      std::cout << "Number: " << num << std::endl;     std::cout << "Float Number: " << fNum << std::endl;     std::cout << "Word: " << word << std::endl;      std::ostringstream oss; // 创建输出流     oss << "Concatenated: " << num << " " << fNum << " " << word;      std::cout << oss.str() << std::endl; // 输出流中的字符串      return 0; } 

这是一些简单的示例，string和stringstream类还有更多的功能和用法，可以根据具体需求查阅C++文档来了解更多信息。