C++ cin cin隨機跳過

Question

我有這個程序，但隨機跳過cin ..我的意思是有時它會，有時它不會。任何想法如何解決這一問題？

int main(){ 


     /** get course name, number of students, and assignment name **/ 
     string course_name; 
     int numb_students; 
     string assignment_name; 
     Assignment* assignment; 

     cout << "Enter the name of the course" << endl; 
     cin >> course_name; 

     cout << "Enter the number of students" << endl; 
     cin >> numb_students; 

     cout << "Enter the name of the assignment" << endl; 
     cin >> assignment_name; 

     assignment = new Assignment(assignment_name); 

     /** iterate asking for student name and score **/ 
     int i = 0; 
     string student_name; 
     double student_score = 0.0; 
     while(i < numb_students){ 

      cout << "Enter the name for student #" << i << endl; 
      cin >> student_name; 
      cout << "Enter the score for student #" << i << endl; 
      cin >> student_score; 
      assignment->addScore(Student(student_name, student_score)); 
      i++; 
     } 
} 

好的我想通了。對於任何人想知道這裏是更新後的代碼：

int main(){ 

    /** get course name, number of students, and assignment name **/ 
    string course_name; 
    int numb_students; 
    string assignment_name; 

    cout << "Enter the name of the course" << endl; 
    getline(cin, course_name); 

    cout << "Enter the number of students" << endl; 
    string temp; 
    getline(cin, temp); 
    numb_students = atoi(temp.c_str()); 

    cout << "Enter the name of the assignment" << endl; 
    getline(cin, assignment_name); 

    Assignment assignment(assignment_name); 

    /** iterate asking for student name and score **/ 
    int i = 0; 
    string student_name; 
    double student_score = 0.0; 
    while(i < numb_students){ 

     cout << "Enter the name for student #" << i+1 << endl; 
     getline(cin, student_name);  
     cout << "Enter the score for student #" << i+1 << endl; 
     getline(cin, temp); 
     student_score = atof(temp.c_str()); 
     assignment.addScore(Student(student_name, student_score)); 
     i++; 
    } 

Answer 1

我猜，你的一些輸入有空格他們，其中>>運營商將其視爲一個特定的輸入項目的結束。 iostreams >>操作符實際上不是爲交互式輸入而設計的，特別是對於字符串 - 您應該考慮使用getline（）來代替。

而且，你是不必要使用動態分配：

assignment = new Assignment(assignment_name); 

會好得多寫爲：

Assignment assignment(assignment_name); 

你應該避免在你的代碼中使用「新」的只要有可能，和而是讓編譯器爲你處理對象的生命週期。