CPP

getline

Make sure you didn't use cin >> str. before calling the function. If you use cin >> str and then want to use getline(cin, str), you must call cin.ignore() before.

string str;
cin >> str;
cin.ignore(); // ignores 
 that cin >> str has lefted (if user pressed enter key)
getline(cin, str);

getline()

getline(cin >> ws, title);

getline c++

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

getline

#include <bits/stdc++.h>
using namespace std;

int main()
{

#ifndef ONLINE_JUDGE
	freopen("input.txt","r",stdin);
	freopen("output.txt","w",stdout);
#endif
int t;
string a,b;
cin>>a;
cin.ignore();  /*must include this otherwise the cin will 
have null space availabe in buffer and getline wont take 
anything as input so we must clear or ignore the space 
availabe in buffer due to previous input */
getline(cin,b);

cout<<a<<b;
}