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c++ - Exit while loop when character | is entered

I am currently reading the book " Programming Principles and Practice Using " and trying to solve a really simple exercise:

" Write a program that consists of a while -loop that (each time around the loop) reads in two int s and then prints them. Exit the program when a terminating '|' is entered."

I do not know how to formulate the condition to break the while loop

#include "std_lib_facilities.h"

int main()
{   int i = 0,j = 0;
    while()
    {
        cin>>i>>j;
        cout<<i<<j<<endl;
    }
}
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1 Answer

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#include <iostream>
#include <string>
#include <cctype>

int main()
{
    int a = 0, b = 0;
    char term;

    // First solution
    while (true)
    {
        std::cin >> a >> b >> term;
        if(term == '|') break;
        else std::cout << a << ' ' << b << std::endl;
    }
    return 0;

    // Second solution
    while(true)
    {
        std::string line;
        std::getline( std::cin, line );
        if(line.find("|") == line.npos)
        {
            for(int i = 0; i< line.size() && ( std::isdigit(line[i]) || line[i] == ' '); i++)
                std::cout << line[i];
            std::cout << std::endl;
        }else break;
    }
}

IMHO 2'nd option is better if you want to stick to STL, first option should be more readable and easier to understand. If you have any questions, feel free to ask


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