Stop taking input when a blank line encounters [closed] - c++

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I am trying to stop the loop when user gives a blank line, otherwise push name and score to a vector pair. But this code is not working.
Input format:
<name><score>
e.g.:
Akash 45
My code is below:
int m;
cin>>m;
vector<pair<string,int>>player;
string name;
int score;
while(1)
{
cin>>name;
if(name.empty())
break;
cin>>score;
player.push_back(make_pair(name,score));
}
Also , I have tried the following:
if(name.length()==0)
while(getline(cin,name))
if (name=="")
None of them worked.
Can anyone help me?

Answer 1

`std::cin >>`
does not return with empty input. When the user wrote just the "Enter" key, the std::cin still wait.
I made the test, this is working :
std::getline(std::cin, name);
if(name.empty())
break;
Edit :
#include <iostream>
#include <vector>
#include <string>
int main()
{
std::vector<std::pair<std::string, int>>player;
std::string name;
int score;
while (1)
{
std::getline(std::cin, name);
if (name.empty())
break;
std::cin >> score;
player.push_back(make_pair(name, score));
// clear the std::cin buffer else the next std::getline won't wait next input
std::cin.seekg(0, std::ios::end);
std::cin.clear();
}
return 0;
}
the
std::cin.seekg(0, std::ios::end);
std::cin.clear();
fix the problem of the second std:getLine

Answer 2

operator>> ignores whitespace, and line breaks are treated as whitespace, so cin>>name will never return a blank string (baring an input failure).
To accomplish what you are attempting, you need to use get::getline() instead to read an entire line at a time. You can then test for blank lines, and can use std::istringstream to parse values from each non-blank line, eg:
vector<pair<string,int>> player;
string line, name;
int score;
while (getline(cin, line) && !line.empty())
{
istringstream iss(line);
if (iss >> name >> score)
player.push_back(make_pair(name, score));
}

Answer 3

There's a small program to demonstrate you how to achieve so:
#include <iostream>
#include <vector>
int main(void) {
std::string name;
std::vector<std::string> nameList;
std::getline(std::cin, name); // statement X
nameList.push_back(name);
for (; ;)
if (name.empty())
break;
else {
std::getline(std::cin, name); // recalling statement X again
nameList.push_back(name);
}
for (int i = 0; i < nameList.size(); i++)
std::cout << nameList[i] << std::endl;
return 0;
}
First of all, let the user input something before going inside the loop directly. As soon as the user hits Enter, the loop will be broken when name.empty() conditions becomes true and returns true and break statement is executed.
In the other hand, as long as the user will hit the Enter key and keep writing something line-by-line, the loop will be executed.
Notice that I've used a For loop in this case, you could do the same trick with a While loop as shown:
while (true)
if (name.empty())
break;
else {
std::getline(std::cin, name); // recalling statement X again
nameList.push_back(name);
}