C++中字符串处理问题及解决方法概述

#include <iostream>
#include <cstring>

int main() {
    char* str = new char[100];   // 分配100字节的内存空间

    strcpy(str, "Hello, World!");

    std::cout << str << std::endl;

    delete[] str;   // 释放内存

    return 0;
}

#include <iostream>
#include <string>
#include <sstream>

int main() {
    std::string str1 = "Hello";
    std::string str2 = "World";

    // 使用字符串连接运算符
    std::string result = str1 + ", " + str2;
    std::cout << result << std::endl;

    // 使用C风格的字符串拼接函数
    char* str3 = new char[100];
    strcpy(str3, str1.c_str());
    strcat(str3, ", ");
    strcat(str3, str2.c_str());
    std::cout << str3 << std::endl;
    delete[] str3;

    // 使用字符串流
    std::stringstream ss;
    ss << str1 << ", " << str2;
    std::cout << ss.str() << std::endl;

    return 0;
}

#include <iostream>
#include <string>

int main() {
    std::string str = "Hello, World!";

    // 查找子字符串
    size_t found = str.find("World");    // 字符串从0开始计数，找到返回下标，找不到返回std::string::npos
    if (found != std::string::npos) {
        std::cout << "Substring found at position: " << found << std::endl;
    }
    
    // 替换部分字符
    str.replace(7, 5, "C++");   // replace的三个参数分别是起始下标、替换长度和替换字符串
    std::cout << str << std::endl;

    return 0;
}