在學生班級之間排序名稱

Question

編輯。我想感謝在我的代碼中幫助過我的兩個人。截至PST 9/25/2014下午7:22，我修復了我的代碼。儘管如此，排序仍然有問題。

所以我想教自己如何使用C++爲了在學校裏領先我的編程課。我已經採用了Java，所以我對編碼的結構比較熟悉，但不完全確定要輸入什麼內容。這個練習問題是：

1）詢問用戶有多少人想進入列表。

2）閱讀3個字符串，然後將該信息轉換爲學生課，並將學生放入一個向量中。

3）按名稱對列表進行排序。 （額外學分將按學號排序）

4）列出每個學生的信息。

5）詢問用戶，而答案是「是」，在列表中找到的名稱和打印信息相關的名稱

而在Java中，這似乎是很容易的，我有一個非常困難時期瞭解C++中發生了什麼。

我目前只有1，2，4和5完成。這是我迄今爲止所擁有的。

#include <iostream> 
#include <string> 
#include <vector> 
#include <algorithm> 
#include <sstream> 
#include <fstream> 
#include <iomanip> 

using namespace std; 

class Student 
{ 
    string myName, myStudentID, myClassID; 
public: 
    Student(string name, string studentID, string classID) 
    { 
     myName = name; 
     myStudentID = studentID; 
     myClassID = classID; 
    } 

    string getName() { return myName; } 
    string getStudentID() { return myStudentID; } 
    void printInfo() { cout << myName << setw(15) << myStudentID << setw(10) << myClassID << endl; } 



}; 

int main() 
{ 
    int num; 
    std::vector<Student> studentList; 
    cout << "How many students do you wish to add to the student list ? " << endl; 
    cin >> num; 


    cin.ignore(); 
    for (int a = 0; a < num; a++) 
    { 

     string inputName, inputStudentID, inputClassID; 
     //get name 
     cout << "Please enter the Student name : "; 
     getline(cin, inputName); 


     //get student ID 
     cout << "Please enter the Student ID number : "; 
     getline(cin, inputStudentID); 


     //get class ID 
     cout << "Please enter the Student class ID : "; 
     getline(cin, inputClassID); 



     Student thisStudent(inputName, inputStudentID, inputClassID); 
     studentList.push_back(thisStudent); 

     cout << endl; 
    } 

    //sort(studentList.begin(), studentList.end()); 
    /* 
    I never figured out how to sort the list by name. 
    I do not know how to compare the name of studentList[0] and studentList[1] 
    to put them in alphabetical order. 
    */ 
    cout << endl;; // FORMATTING 

    cout << "The student list has a size of " << studentList.size() << endl; 

    cout << endl;; // FORMATTING 


    cout << "Student Name" << setw(15) << "Student ID" << setw(10) << "Class ID" << endl; 
    for (int a = 0; a < studentList.size(); a++) 
    { 
     studentList[a].printInfo(); 
    } 

    cout << endl;; // FORMATTING 


    string searchedName; 
    char answer; 
    do 
    { 
     cout << endl;; // FORMATTING 
     cout << "Please type the name of the person you want to search for: "; 
     getline(cin, searchedName); 
     for (int a = 0; a < studentList.size(); a++) 
     { 
      if (searchedName.compare(studentList[a].getName()) == 0) 
      { 
       studentList[a].printInfo(); 
       break; 
      } 
      else 
       if (a == (studentList.size() - 1)) //If went to end of the list, tell them name not found. 
        cout << "There is no " << searchedName << " in the list. \n"; 


     } 

     cout << "Would you like to search for another person? \n"; 
     cout << "Y for Yes, N for No. \n"; 
     cin >> answer; 
     cin.ignore(); 

    } while (answer == 'Y' || answer == 'y'); 


    return 0; 




} 

Answer 1

您可以創建一個靜態類學生比較函數的std ::排序

class Student 
{ 
    string myName, myStudentID, myClassID; 
// ... 
    static bool compare_name(const Student & lStudent, const Student & rStudent) 
     {return (lStudent.myName < rStudent.myName);} 
}; 
// ... 
    std::sort(studentList.begin(), studentList.end(), Student::compare_name); 

，或者如果你的編譯器支持lambda函數的使用方法：

std::sort(studentList.begin(), studentList.end(), 
     [studentList](const Student & lStudent, const Student & rStudent) 
      {return (lStudent.myName < rStudent.myName);});