字符串短语以 space 结尾？

Question

我正在编写一个简单的代码来了解有关字符串的更多信息。当我运行我的代码时，它不会打印我的姓氏。有人可以解释为什么吗？我使用字符串短语来存储它，它似乎只存储了我的名字。这是代码。

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

int main()
{
    cout << "Exercise 3B" << endl;
    cout << "Kaitlin Stevers" << endl;
    cout << "String arrays" << endl;
    cout << endl;
    cout << endl;
    char greeting[26];
    cout << "Please enter a greeting: " << endl;
    cin >> greeting;
    cout << "The greeting you entered was: " << greeting << endl;
    string phrase;
    cout << "Enter your full name " << endl;
    cin >> phrase;
    cout << greeting << ", how are you today " << phrase << "?" << endl;
    return 0;
}

Answer 1

当您调用 cin >> phrase; 时，它只读取字符串直到第一个非 space 字符。如果您想在您的名字中包含 space，最好使用 getline(cin,phrase);。

重要提示：getline() 将读取流缓冲区中的任何内容，直到第一个 \n。这意味着当您输入 cin >> greeting; 时，如果您按下 ENTER，getline() 将读取 \n 之前尚未读取的所有内容，这对您的 phrase 变量来说没有意义，使它成为一个空字符串。一个简单的方法是调用 getline() 两次。例如

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

int main()
{
    cout << "Exercise 3B" << endl;
    cout << "Kaitlin Stevers" << endl;
    cout << "String arrays" << endl;
    cout << endl;
    cout << endl;
    char greeting[26];
    cout << "Please enter a greeting: " << endl;
    cin >> greeting;  //IMPORTANT: THIS ASSUME THAT GREETING IS A SINGLE WORD (NO SPACES)
    cout << "The greeting you entered was: " << greeting << endl;
    string phrase;
    cout << "Enter your full name " << endl;
    string rubbish_to_be_ignored;
    getline(cin,rubbish_to_be_ignored); //this is going to read nothing
    getline(cin, phrase); // read the actual name (first name and all)
    cout << greeting << ", how are you today " << phrase << "?" << endl;
    return 0;
}

假设您将该代码存储在文件 Whosebug.cpp 中。示例运行：

Chip Chip@04:26:00:~ >>>  g++ Whosebug.cpp -o a.out
Chip Chip@04:26:33:~ >>>  ./a.out
Exercise 3B
Kaitlin Stevers
String arrays


Please enter a greeting: 
Hello  
The greeting you entered was: Hello
Enter your full name 
Kaitlin Stevers
Hello, how are you today Kaitlin Stevers?

测试于 ubuntu 14.04

Answer 2

I used string phrase to store it and it only appears to have stored my first name.

有道理。

cin >> phrase;

在输入中遇到空白字符时将停止读取。

要阅读全名，您可以使用以下方法之一。

两次调用 cin >>。

std::string first_name;
std::string last_name;
cin >> first_name >> last_name;

使用getline读取整行。 getline 将读取一行中的所有内容，包括空白字符。
```
getline(cin, phrase);
```

字符串短语以 space 结尾？

String phrase ends at space?

c++

string

c-strings