[C++] 키보드 입출력 cin / cin.get / cin.getline / getline 이해와 사용법, 차이점

1. cin - istream 클래스의 인스턴스 / '>>' 연산자와 주로 동작함

How to use :

example :

#include <iostream>     // std::cin, std::cout

int main () {
  char c;

  std::cout << "Enter the name of an existing text file: ";
  std::cin >> c;    		 // get char

  std::ifstream is(str);     // open file

  char c;
  while (is.get(c))          // loop getting single characters
    std::cout << c;

  is.close();                // close file

  return 0;
}

example :

feature :

-> 입력버퍼에서 공백, \n 무시 제외한 값을 저장

*  \n 버퍼가 남음

 

 

2. cin.get()

How to use :

#include <iostream>

// (1) single character
int get();
istream& get (char& c);


// (2) c-string
istream& get (char* s, streamsize n);
istream& get (char* s, streamsize n, char delim);


// (3) stream buffer
istream& get (streambuf& sb);
istream& get (streambuf& sb, char delim);

example :

// istream::get example
#include <iostream>     // std::cin, std::cout
#include <fstream>      // std::ifstream

int main () {
  char str[256];

  std::cout << "Enter the name of an existing text file: ";
  std::cin.get (str,256);    // get c-string

  std::ifstream is(str);     // open file

  char c;
  while (is.get(c))          // loop getting single characters
    std::cout << c;

  is.close();                // close file

  return 0;
}

feature :

-> 입력버퍼에서 하나의 문자만 저장 공백, \n 포함함

3. cin.getline()

How to use :

#include <iostream>
istream& getline (char* s, streamsize n );
istream& getline (char* s, streamsize n, char delim );

example :

// istream::getline example
#include <iostream>     // std::cin, std::cout

int main () {
  char name[256], title[256];

  std::cout << "Please, enter your name: ";
  std::cin.getline (name,256);

  std::cout << "Please, enter your favourite movie: ";
  std::cin.getline (title,256);

  std::cout << name << "'s favourite movie is " << title;

  return 0;
}

feature :

-> 공백, \n 입력 받음 문자열 문자 받음

-> 마지막 문자 NULL

-> getline() 과 다른함수임

4. getline()

How to use :

#include <string>
istream& getline (istream& is, string& str, char delim);
istream& getline (istream& is, string& str);

example :

// extract to string
#include <iostream>
#include <string>

int main ()
{
  std::string name;

  std::cout << "Please, enter your full name: ";
  std::getline (std::cin,name);
  std::cout << "Hello, " << name << "!\n";

  return 0;
}

 

C++ Reference
cin : www.cplusplus.com/reference/iostream/cin/?kw=cin
cin.get() : www.cplusplus.com/reference/istream/istream/get/?kw=cin.get
cin.getline() : www.cplusplus.com/reference/istream/istream/getline/
getline() : www.cplusplus.com/reference/string/string/getline/

고마운분 : https://modoocode.com/213