Storing the input in the same variable the second time fails,

[Hashirama senju]

I am writing a simple program to check if the input is an integer greater than 0. I have noticed that strings and characters get converted to zero when I do cin >> variable. So that means only integers above 0 can be validated. I don't need zero here anyway. Here is the code. My problem is the title.

 std::cout << "Write an integer greater than 0:\n";
    int n;
    while(1){
        std::cout << ">";
        std::cin >> n;
        if(n > 0){
            break;
        }
        else{
            std::cout << "You did not enter an integer greater than 0. Try again!\n";
        }
    }
    std::cout << "You entered an integer greater than 0!\n";

My problem is that if I enter a wrong input, it keeps looping and looping the else branch. It does not let me input again. However, I have told it to get the input by that std::cin >> n; when the while, loops again.

[dub1987]

I'm not sure what you are trying to accomplish with while(1)
while what is 1? You have to tell the compiler what you mean.

int main()
{
	int n;

	cout << "Enter a number greater than 0:\n";
	cin >> n;

	while (n <= 0)
	{
		cout << "Integer not greater than 0. Please try again.\n";
		cout << "Enter a number greater than 0:\n";
		cin >> n;
	}	
	return 0;
}

[Hashirama senju]

What I want to achieve with while(1) is an infinite loop.
Your method does not work either. Like in my method, the second time I try to store in n does not work. I noticed that it happens only when I enter a string or a character. It works fine when I enter 0. That means my earlier assumption that characters are converted to 0 is false.

I can't think of another way :/ . I will search google.

I still do not understand why its failing when I enter a character or a string.

[dub1987]

The method I provided should loop until you enter an integer greater than 0. I can't remember if I tested it using a char or a string though. I'm not sure if I followed what you are trying to accomplish.

[S G H]

When input fails, the fail bit is set. Reset it with: std::cin.clear();

Side note: Despite seeing you only have 6 posts, may god bless you for preferring std:: instead of "using namespace". Not sarcasm, very serious.

[Hashirama senju]

Ok, I have found the correct solution. It's this:

std::cout << "Write an integer:\n>";
    int n;
    std::cin >> n;
    while (!std::cin) {
        std::cout << "ERROR, you are allowed to enter an integer only.Try again!\n>";
        std::cin.clear();
        std::cin.ignore(10000,'\n');
        std::cin >> n;
    }

When the input is wrong, it's left in the buffer. We need to clear the input buffer using std::cin.ignore(). I don't really understand that function. Is it ignoring the first 10000 characters in the buffer? What's the use of the end of line character?
I have read the reference documentation in this site but I did not understand anything there.

@EssGeEich, yes. I am happy that I started using that way.

[S G H]

Oh right, you need to ignore it.
Basically it will erase up to 10000 characters, unless the newline character is found (it gets erased, too).
You should use std::numeric_limits<std::streamsize>::max() (include <limits>) instead of 10000: It is guaranteed to erase as much as possible.

Optimal call: std::cin.ignore(std::numeric_limits<std::streamsize>::max(),'\n');

Edit: I'm sorry, I just woke up. Corrections.