how to detect 'Enter Key' in c++?

Question

I want to detect enter pressed to break loop. If user press 2 enters in a row, loop breaks. I'm using vector to store user input. All variable's type is integer.

#include <iostream>
#include <vector>

using namespace std;

int main()
{   int buffer;
    vector<int> frag;
    do
    {
        cin >>buffer;
        frag.push_back(buffer);
    }while(frag.end()!='\n');


}

How can I escape from error message "no match for 'operator!=' (operand types are 'std::vector::iterator....."?

what is "some codes" ? please provide a [mcve]. in particular, what is `frag`? — 463035818_is_not_an_ai, Oct 11 '17 at 14:39
Have a look a the following posts: [Press Enter to Contine](https://stackoverflow.com/questions/903221/press-enter-to-continue) and [Detect hitting Enter Key in C++](https://stackoverflow.com/questions/26325932/detect-hitting-enter-key-in-c). — Ron, Oct 11 '17 at 14:48
I did, but it didn't solve my problem. I need to compare integer versus enter. — Yohan Kim, Oct 11 '17 at 14:52
Possible duplicate of [Detect hitting Enter Key in C++](https://stackoverflow.com/questions/26325932/detect-hitting-enter-key-in-c) — norok2, Oct 11 '17 at 14:57
Possible duplicate of [Press Enter to Continue](https://stackoverflow.com/questions/903221/press-enter-to-continue) — Stephen, Oct 11 '17 at 16:02

Raindrop7 · Answer 1 · 2017-10-11T19:12:17.240

0

You can compare std::cin.get against \n:

std::vector<int> vecInt;
char c;

while(std::cin.peek() != '\n'){
    std::cin.get(c);

    if(isdigit(c))
        vecInt.push_back(c - '0');
}

for (int i(0); i < vecInt.size(); i++)
    std::cout << vecInt[i] << ", ";

The input : 25uA1 45p
The output: 2, 5, 1, 4, 5,

If you want to read in two integer values so after hitting Enter key for the second time it will stop reading:

std::vector<int> vecInt;
int iVal, nEnterPress = 0;


while(nEnterPress != 2){

    if(std::cin.peek() == '\n'){
        nEnterPress++;
        std::cin.ignore(1, '\n');
    }
    else{
        std::cin >> iVal;
        vecInt.push_back(iVal);
    }
}

for (int i(0); i < vecInt.size(); i++)
    std::cout << vecInt[i] << ", ";

Input:  435  (+ Press enter )
        3976 (+ Press enter)

Output: 435, 3976,

edited Oct 11 '17 at 19:12

answered Oct 11 '17 at 14:47

Raindrop7

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Thanks, but I need integer type, not char for a vector – Yohan Kim Oct 11 '17 at 14:55
it only take one input. I need multiple input until two enters. – Yohan Kim Oct 11 '17 at 18:01
`I need multiple input until two enters` You mean with "two" "double press" enter to stop reading or you mean until character `2` enters? – Raindrop7 Oct 11 '17 at 19:14

how to detect 'Enter Key' in c++?

1 Answers1