cin

How can i read in a specific format using cin? Example:-for reading a complex number, I would like the user to enter it as usual:x+yi, so i want something like this: cin>>x>>"+">>y>>"i"; But this is giving an error.What is the right way?Help greatly appreciated. A very simple solution: char plus,img; double x,y; cin>> x >> plus >> y >> img; if (plus!='+' || img!='i') ...error In "real life" code you build/use a class complex , and overload the operator >>. I try it in Ideone: http://ideone.com/ZhSprF #include <iostream> using namespace std; int main() { char plus{},img{}; double x{},y{}; cin>>

I'm sorry but I'm quite new to C++ but not programming in general. So I tried to make a simple encryption/decryption. However when I added the modification to my previous code (so there isn't two programs for encrypting and decrypting) I found that the code 'getline()' method no longer works. Instead it's just ignoring it when the code is ran. Here's the code: int main(){ std::string string; int op = 1; //Either Positive or Negative srand(256); std::cout << "Enter the operation: " << std::endl; std::cin >> op; std::cout << "Enter the string: " << std::endl; std::getline(std::cin, string); /

I have this program, but cin in randomly skips.. I mean sometimes it does, and sometimes it doesn't. Any ideas how to fix this? int main(){ /** get course name, number of students, and assignment name **/ string course_name; int numb_students; string assignment_name; Assignment* assignment; cout << "Enter the name of the course" << endl; cin >> course_name; cout << "Enter the number of students" << endl; cin >> numb_students; cout << "Enter the name of the assignment" << endl; cin >> assignment_name; assignment = new Assignment(assignment_name); /** iterate asking for student name and score **

This question already has an answer here: Infinite loop with cin when typing string while a number is expected 4 answers Please read the following code: #include <iostream> #include <cstdlib> int main() { std::cout << "Please input one integer." << std::endl; int i; while (true) { std::cin >> i; if (std::cin) { std::cout << "i = " << i << std::endl; break; } else { std::cout << "Error. Please try again."<< std::endl; std::cin.ignore(); std::cin.clear(); } } std::cout << "Thank you very much." << std::endl; std::system("pause"); return 0; } When I give std::cin an invalid input, such as w ,

I was working on the following code. #include <iostream> int main() { std::cout << "Enter numbers separated by whitespace (use -1 to quit): "; int i = 0; while (i != -1) { std::cin >> i; std::cout << "You entered " << i << '\n'; } } I know that using while (std::cin >> i) would have been better but I don't understand a specific occurrence. If I provide an invalid input, the loop becomes infinite because the Input Stream enters a failbit state. My question is that what happens to the input variable i ? In my case, it becomes 0 regardless of the previous value entered. Why does it change to 0

I'm trying to setup an input checking loop so it continuously ask the user for a valid (integer) input, but it seems to get trapped in an infinite loop. I've searched for solutions and tried to ignore() and clear() , but it still doesn't stop. Could you please correct me where I'm wrong here? int num; cin >> num; while (cin.fail()) { cin.ignore(); cin.clear(); cout << "Enter valid number: " << endl; cin >> num; } R Sahu When the stream is in an state of error, cin.ignore(); does not do anything. You need to call cin.clear() first before calling cin.ignore() . Also, cin.ignore() will ignore

My question is based on this simple code: #include <string> using namespace std; int main() { string buf; while (cin >> buf && !buf.empty()) { cout << "input is " << buf << "\n"; } return 0; } The operator>> of cin (which is an object of type basic_istream) reads and discards any leading whitespace (e.g. spaces, newlines, tabs). Then operator>> reads characters until the next whitespace character is encountered. The operators returns finally the stream itself, cin. It shouldn't be possible to enter an empty string without also setting at least one of the iostates eof, fail or bad? And

I am trying to read an unsigned int using cin as follows: #include <limits.h> #include <iostream> using namespace std; int main(int argc, char* argv[]) { unsigned int number; // UINT_MAX = 4294967295 cout << "Please enter a number between 0 and " << UINT_MAX << ":" << endl; cin >> number; // Check if the number is a valid unsigned integer if ((number < 0) || ((unsigned int)number > UINT_MAX)) { cout << "Invalid number." << endl; return -1; } return 0; } However, whenever I enter a value greater than the upper limit of unsigned integer ( UINT_MAX ), the program displays 3435973836 . How do I

How can I enter an input without causing the code to stop executing? I have been searching for an answer during the last 20 minutes without result. cin >> string; pauses the code AFAIK. Would I need to use mulithreading, or is there a better way? (I don't even know if multithreading would work.) I've recently started learning c++, I am a beginner to say the least, so please explain thoroughly and include any library I might need, thank you. There are two algorithms for getting input without blocking (pausing). The first is polling, the second is by event (interrupt). Polling For Input Polling