CODEWITHSUNDEEP
c++while-loopcininfinite
Aurora_rainbow
Aurora_rainbow

Reputation: 31

not exiting while loop with cin as condition c++

I know that this is a common question but i could not find any solution to this question without using vectors and ctrl + d/c. I have encounter a infinite while loop while using cin to get a unknown amount of integer. the while loop does not stop executing even after a enter in pressed. Thanks a lot!

while(cin >> num)
{
    num--;
    sizeB = 0;
    setB[sizeB] = num;
    sizeB++;
}
cin.ignore();
cin.clear();

Upvotes: 1

Views: 1843

Answers (2)

kzagar
kzagar

Reputation: 355

It is possible to use getline function to get data line-by-line, then read values via a stringstream:

#include <iostream>
#include <stdio.h>
#include <sstream>

using namespace std;

int main() {
  string line;
  while(getline(cin, line)) {
    stringstream str_stream(line);
    int num;
    while(str_stream >> num) {
      cout << "..." << num << "..." << endl;
    }
    cout << "----" << endl;
  }
}

Upvotes: 2

Exceptyon
Exceptyon

Reputation: 1582

while takes a bool argument. In your code, cin >> num returns an istream&, that is converted calling istream::operator bool() (and I'd guess evaluates to true if the stream is not closed)

read a string and convert it to int, break when the string is empty:

while (1) {
   std::string theString;
   std::getline(std::cin, theString);
   if (theString.empty())
      break;
   int num= atoi(theString.c_str());
   ...
}

Upvotes: 0

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