如何在C ++中检测Enter？

Question

I use cin to input some numbers into my program. Here is the input format:

1' '2' '3' '4' '5' ''\n'    //One item includes one number and one space. There is an Enter at the end of input.

I need to input these number one by one into an array until there is an Enter. But the cin cannot detect the '\\n' . Does anyone have good idea for that?

Answer 1

Since the answer-in-commentor has not posted an answer...

I guess you were initially reading with int x; ... cin >> x . The istream::operator>>(int) function skips leading whitespace, and newlines count as whitespace. So with that approach you could not distinguish 1 2 from 1\\n2 .

Instead you need to use a function that preserves newlines at least (if not all whitespace). std::getline is a good function for this purpose. You can then turn the line into a stream by using a std::stringstream .

For example:

#include <vector>
#include <string>
#include <sstream>
#include <iostream>

int main()
{
    std::vector<int> numbers;
    std::string line;

    std::getline(std::cin, line);

    std::istringstream iss(line); 

    for( int x; iss >> x; )
        numbers.emplace_back(x);

    // Output to test that it worked
    for ( int x : numbers )
        std::cout << x << " ";
    std::cout << '\n';
}