c++ check if cin didn't get int
To check if cin
didn't get an integer in C++, you can use the fail
function or the >>
operator to check the state of the input stream. Here are the steps:
Include the necessary header file:
#include <iostream>
Declare a variable to store the input:
int num;
Read the input using
cin
:std::cin >> num;
Check the state of the input stream using the
fail
function or the>>
operator:Using the
fail
function:cpp if (std::cin.fail()) { // Handle the case when cin did not get an integer }
Using the
>>
operator:cpp if (!(std::cin >> num)) { // Handle the case when cin did not get an integer }
Both the fail
function and the >>
operator return true
if the input was successful and false
otherwise.
- Handle the case when
cin
did not get an integer. This could involve displaying an error message, clearing the input stream, or taking any other appropriate action.
Note: It is important to clear the input stream after a failed input to avoid getting stuck in an infinite loop. You can clear the input stream using the clear
function and ignore any remaining characters using the ignore
function:
std::cin.clear();
std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
These steps will allow you to check if cin
didn't get an integer in C++ and handle the situation accordingly.