C++ for循环c+中的变量范围+；奇怪的行为

我在for循环中声明了一个变量，在第二次迭代中，该变量在声明之前仍然存在。这是密码

std::map<std::string,Schema> schemas;
std::vector<std::string> schemaFolders = fileUtil.getSubFolders(BASE_FOLDER);

  for(int i = 0; i < schemaFolders.size(); i++){
          std::string folder(BASE_FOLDER);
          folder += "/";
          folder += schemaFolders[i];
          Schema  schema(folder);
          schema->loadDatabases();
          schemas[schemaFolders[i]] =  schema;
          std::cout<<std::endl<<schemas[schemaFolders[0]].getSchemaFolder()<<std::endl;
  }

和Equals运算符

Schema & Schema::operator=(const Schema& other){
    this->schemaFolder = other.schemaFolder;
    this->databases =  other.databases;
    this->curDb = other.curDb;

    return *this;
}

---

请注意，调试日志输出总是索引

0

，而不是

i

应该工作吗？请发布您的

Schema&operator=（const Schema&）的实现也是。在这里发布问题之前提取一个最小的示例。请参见，我添加了equals操作符。cout向我展示了与第一个schemaFolder对应的键一起存储的模式值在每次迭代中是如何变化的（这是我无法理解的）
Schema::Schema( const Schema& other ){
    this->schemaFolder = other.schemaFolder;
    this->databases =  other.databases;
    this->curDb = other.curDb;

}

Schema & Schema::operator=(const Schema& other){
    this->schemaFolder = other.schemaFolder;
    this->databases =  other.databases;
    this->curDb = other.curDb;

    return *this;
}