我有两个迭代器和一个带有元素字符串和size_t的列表 我想要做的是将我的student_id和成绩添加到结果列表中。
答案 0 :(得分：1)
在您的解释和添加一些内容后，我认为您的错误在于使用std::string::compare。我测试了以下代码（避免使用PropertyInfo[] infos = yourObjectInstance.GetType().GetProperties();
int count = 0;
for(int i = 0; i < infos.Length; i++)
{
if(infos[i].PropertyType == typeof(string))
{
string stringValue = infos[i].GetValue(yourObjectInstance).ToString().Trim();
if(!string.IsNullOrEmpty(body))
{
count++;
}
continue;
}
if(infos[i].GetValue(yourObjectInstance) != null)
{
count++;
}
}
if(count == 0)
{
// Handle error
}
// Create record
，因为未定义addRegister）：
Transcript请注意我如何使用#include <iostream>
#include <list>
#include <algorithm>
typedef struct Records_r {
std::string name; // Name of the records
std::string student_id;
std::list<std::pair<std::string, size_t>> grades; // List of (course, grade) pairs
} Records;
typedef std::list<std::pair<std::string, size_t>>::const_iterator Personaliteraattori;
std::list<std::pair<std::string, size_t>> findCourseResults(const std::list<Records>& registry, const std::string& course) {
std::list<std::pair<std::string, size_t>> results;
for (std::list<Records>::const_iterator it = registry.begin(); it != registry.end(); ++it) {
for (Personaliteraattori itt = it->grades.begin(); itt != it->grades.end(); ++itt) {
if (itt->first.compare(course) == 0) {
results.push_back(std::make_pair(it->student_id, itt->second));
}
}
}
return results;
}
int main()
{
std::string s = "Record of student_123456";
std::string id = "123456";
std::list<std::pair<std::string, size_t>> grades;
grades.emplace_back("Math", 2);
grades.emplace_back("Basic Math", 4);
grades.emplace_back("Advanced Math", 5);
grades.emplace_back("Math 1", 3);
Records t;
t.name = s;
t.student_id = id;
t.grades = grades;
std::list<Records> reg;
reg.push_back(t);
t.name = "Record of student_34567";
t.student_id = "34567";
t.grades.clear();
t.grades.push_back(std::pair<std::string,size_t>("Math",1));
t.grades.push_back(std::pair<std::string,size_t>("Catalan",5));
t.grades.push_back(std::pair<std::string,size_t>("Basic Math",9));
reg.push_back(t);
for (auto& tr : reg ) {
std::cout << "Name: " << tr.name << std::endl;
std::cout << "Student id: " << tr.student_id << std::endl;
std::cout << "Grades:" << std::endl;
std::for_each(tr.grades.begin(), tr.grades.end(), [](std::pair<std::string, size_t> e)
{
std::cout << e.first << " : " << e.second << std::endl;
});
}
while(true){
std::cout<<"Enter a lecture: ";
std::string lecture;
std::getline(std::cin, lecture);
std::list<std::pair<std::string, size_t>> results = findCourseResults(reg,lecture);
for (auto& tr: results)
{
std::cout<<"StudentId: "<<tr.first<<" grades: "<<tr.second<<std::endl;
}
}
return 0;
}
功能。此代码生成所需的输出：
std::string::compare