The difference is thatstd::getline — as the name suggests — reads a line from the given input stream (which could be, well, std::cin) and operator>> reads a word1. That is, std::getline reads till a newline is found and operator>> reads till a space (as defined by std::isspace) and is found. Both remove their respective delimiter … Read more
Remember that your code is equivalent to: while (std::cin.operator>>(value)) { } Or: while (1) { std::cin >> value ; if (!std::cin) break ; } The “code” always tries to read from std::cin into value before testing std::cin. Let’s look at the quote: […] The input operator (§ 1.2, p. 8) returns its left operand, which … Read more
All of the existing answers are excellent, but all are specific to your particular task. Ergo, I wrote a general touch of code that allows input of comma separated values in a standard way: template<class T, char sep=’,’> struct comma_sep { //type used for temporary input T t; //where data is temporarily read to operator … Read more
Reason for Infinite loop: cin goes into a failed state and that makes it ignore further calls to it, till the error flag and buffer are reset. cin.clear(); cin.ignore(100, ‘\n’); //100 –> asks cin to discard 100 characters from the input stream. Check if input is numeric: In your code, even a non-int type gets … Read more
This: cin>>n; Is reading the number only. It leaves the trailing ‘\n’ on the stream. So your first call to getline() is reading an empty line containing just a ‘\n’ It is best not to mix the use of operator>> and std::getline(). You have to be very careful on whether you have left the newline … Read more
cout << “Press Enter to Continue”; cin.ignore(); or, better: #include <limits> cout << “Press Enter to Continue”; cin.ignore(std::numeric_limits<streamsize>::max(),’\n’);
Try: std::cout << std::numeric_limits<int>::max() << std::endl; // requires you to #include <limits> int on your system is likely a 32-bit signed two’s complement number, which means the max value it can represent is 2,147,483,647. Your number, 3,999,999,999, is larger than that, and can’t be properly represented by int. cin fails, alerting you of the problem. … Read more
Most likely you are trying to read a string after reading some other data, say an int. consider the input: 11 is a prime if you use the following code: std::cin>>number; std::getline(std::cin,input) the getline will only read the newline after 11 and hence you will get the impression that it’s not waiting for user input. … Read more
The \n is left in the input stream as per the way operator>> is defined for std::string. The std::string is filled with characters from the input stream until a whitespace character is found (in this case \n), at which point the filling stops and the whitespace is now the next character in the input stream. … Read more
Your code is correct. If you were interactively inputting, you would need to send a EOF character, such as CTRL-D. This EOF character isn’t needed when you are reading in a file. This is because once you hit the end of your input stream, there is nothing left to “cin”(because the stream is now closed), … Read more