c++ - How do I stop this from infinitely repeating, but still keep the loop? -

on line 33, there break stop code repeating indefinitely, take part in while loop.

the code:

#include <iostream> using namespace std; int main() { while (true){     {         cout << "this program counts twos number inputted user." << endl;         cout << "input number start counting." << endl;         int input;         cin >> input;         if (!cin.fail())//fails if input not integer         {             if (input < 0)//makes sure numbers positive             {                 cout << "that not positive number. try again?" << endl;             }             else if (input % 2 != 0) // makes sure numbers             {                 cout << "that not number. try again?" << endl;             }             else{                 (int = 0; <= input; += 2) //uses loop counting once know number even.                 {                     cout << << endl;                  }             }          }         if (cin.fail())//returns when input other integer.          {             cout << "that not digit, try again." << endl;             break;         }     } } return 0; } 

if guys me find why repeats, help.

you need add break statement after loop in order exit loop. without break loop execute , print output , control fall end of while loop start @ top of loop.

i suggest changing if (cin.fail()) else checking if (!cin.fail()). need ignore rest of input , clear error flags if want loop again.

you had set of brackets in while loop. changes code be:

#include <iostream> #include <limits> using namespace std; int main() {     while (true)     {         cout << "this program counts twos number inputted user." << endl;         cout << "input number start counting." << endl;         int input;         cin >> input;         if (!cin.fail())//fails if input not integer         {             if (input < 0)//makes sure numbers positive             {                 cout << "that not positive number. try again?" << endl;             }             else if (input % 2 != 0) // makes sure numbers             {                 cout << "that not number. try again?" << endl;             }             else{                 (int = 0; <= input; += 2) //uses loop counting once know number even.                 {                     cout << << endl;                  }                 break;  // exit while loop             }          }         else //else when input other integer.          {             cout << "that not digit, try again." << endl;             cin.clear();  // reset error flags             cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n'); // clear input         }     }     return 0; }