cin

问题 So, I read a string using cin.getline(str,10,'h') where as you can see I have used a custom delimiter 'h' and want to read a maximum of 9 characters. After doing this, I use cin>>n to read an integer into my int variable n. #include <iostream> using namespace std; int main() { int n; char str[100]; cin.getline(str, 10, 'h'); cout<<str<<'-'<<endl; cout<<"Enter a number:"; cin>>n; cout<<n; return 0; } Suppose I pass the following input 2 3 pl32 which is a '\n' followed by "2 3 pl32". I expect

问题 I was asked to enter an hour and a minute on the same line. But when I enter the hour, it automatically goes to a new line, and I'm only able to enter the minute on the next line. However, I want to enter the hour and minute on the same line with a colon between them. It should look like this Time: 4:54 But my code produces this: Time: 4 54 cout << "\n\tTime: "; cin >> timeHours; cin.get(); cin >> timeMinutes; 回答1: The behavior depends on the input provided by the user. Your code works as you

问题 I have gone through many existing answers here StackOverflow, but I am still stuck. code: int c; cin >> c; if(cin.fail()) { cout << "Wrong Input"; cin.clear(); cin.ignore(INT_MAX, '\n'); } else { cout << c*2; } If I enter wring input e.g s instead of an integer, it outputs Wrong Input . However, if I enter an integer, and then I enter a string, it ignores the string and keep outputting the previous integer result, hence it does not clears the cin buffer, and the old value of c keeps on

问题 I came across this in my readings... while(!(std::cin >> array[i])) { std::cin.clear(); while(std::cin.get()!= '\n') continue; std::cout << "enter a new input: "; } And, I don't really understand how the error handling is working. std::cin.clear() is used but the code continues to get characters from the cin object in the next line and then uses a continue statement. What exactly does the clear do if it doesn't clear the cin? Thank you. 回答1: what cin.clear() does is to clear the cin stream's

问题 I came across this in my readings... while(!(std::cin >> array[i])) { std::cin.clear(); while(std::cin.get()!= '\n') continue; std::cout << "enter a new input: "; } And, I don't really understand how the error handling is working. std::cin.clear() is used but the code continues to get characters from the cin object in the next line and then uses a continue statement. What exactly does the clear do if it doesn't clear the cin? Thank you. 回答1: what cin.clear() does is to clear the cin stream's

问题 How does std::cin object deal with different types while it is an instance of basic_istream<char> ( istream )? 回答1: The class std::basic_istream<CharT, Traits> models an input stream of characters of type CharT . It provides both relatively low-level and relatively high-level access to that input stream. You can, for example, call std::cin.get() in order to retrieve the next character from the input stream; this will always return CharT , since that's the underlying type of characters in the

问题 How does std::cin object deal with different types while it is an instance of basic_istream<char> ( istream )? 回答1: The class std::basic_istream<CharT, Traits> models an input stream of characters of type CharT . It provides both relatively low-level and relatively high-level access to that input stream. You can, for example, call std::cin.get() in order to retrieve the next character from the input stream; this will always return CharT , since that's the underlying type of characters in the

问题 I am using get.fail() to check if there's any char in the input, and if there is I would like to give the user a chance to re-enter. However, the program seems to still accept the user input whenever there's an integer in front of the input no matter the case. Say w1 and 1w , the program will tell the user that the it only accepts integers while the latter one accepts the input and moves over to the next line which then causes another problem. void userChoice(int input){ switch(input) { case

问题 I would like to know if it's possible to have multiple while (cin>>(variable)) as in the following code: #include <iostream> #include <vector> using namespace std; int main() { vector<int> v1, v2; int input; while (cin>>input) v1.push_back(input); while (cin>>input) v2.push_back(input); return 0; } The logic of my program is to let user define the number of elements and value of each element in two sets of int vectors. However, I realized that after entering the first set of numbers for the

问题 I would like to know if it's possible to have multiple while (cin>>(variable)) as in the following code: #include <iostream> #include <vector> using namespace std; int main() { vector<int> v1, v2; int input; while (cin>>input) v1.push_back(input); while (cin>>input) v2.push_back(input); return 0; } The logic of my program is to let user define the number of elements and value of each element in two sets of int vectors. However, I realized that after entering the first set of numbers for the