C ++中的空格识别

Question

My code has to identify whitespace characters using cin, so when I use space as an input it should identify the space. How do I do this?

Answer 1

You can use std::noskipws to disable the whitespace skipping that std::cin does by default:

#include <iostream>
#include <iomanip>

int main() {
  char c;
  std::cin >> std::noskipws;
  while (std::cin >> c) {
    if (c == ' ')
      std::cout << "A space!" << std::endl;
  }
  return 0;
}

Answer 2

string str;
getline(cin, str); // get the whole line

If you want to deal with c-strings you could use the mentioned cin.getline(....) which is different from strings getline .

Answer 3

Cin breaks on whitespace, of any kind. If you need to read an entire line, you need to use the get line function:

getline(cin, line);

Where line is a std::string. This will still cut off any new lines or carriage returns.

To test the string for spaces examine every character in the string and compare it to the space character " ". That is left as an exercise for the reader ;)

Answer 4

Use cin.getline to read the line with the space.

http://www.cplusplus.com/reference/iostream/istream/getline/