c++ - 如何让程序在打印出 while/if 语句之前请求输入字符串 "course"

Question

如何在不切换程序中提问顺序的情况下做到这一点？在询问类(class)之前，我想了解他们的年龄。但是，一旦输入年龄，程序就会自动继续打印 while/if 语句。

#include<iostream>
#include<string>
using namespace std;

int main()
{

    int age; //Declares the variable "age"
    string name;
    string course;


    cout << "Hi\n"; //Prints out "Hello World"
    cout << "What is your name? ";
        getline(cin, name);
    cout << "\nHow old are you ? ";  //Ask the user their age
        cin >> age; //Records the value entered by user
    cout << "What course are you picking up in university ? ";
        getline(cin, course);

    //If number entered is smaller than 0, print the following message
    while (age < 0 ) {
        cout << "\nYou can't be younger than 0 years old.";
        cout << "\nPlease try again";

        cout << "\n\nHow old are you ? ";
        cin >> age;
    }

    //If number entered is larger than 100, print the following message
    if (age > 100) {
        cout << "\nYou are such a blessed person !\n\n";
    }

    //If number entered is between 1 and 99, print the following message
    if (age > 1 && age < 99) {
        cout << "Your name is " << name << " ,and you are " << age << " years old.";
        cout << "\n You are planning on taking " << course << " in university.";
    }

    return 0;
}

Answer 1

如果在 cin >> 之后使用 getline()，getline() 会将这个换行符视为前导空格，它只是停止阅读。

解决方法:

• 在调用 getline() 之前调用 cin.ignore()

或者

• 进行虚拟调用 getline() 以使用 cin>> 中的尾随换行符