c++ - While loop and bool make program end -

code analyzes integer , asks user if wants analyze integer @ end. have set in while loop run when 'again' true. @ end user inputs 'n' no, not run number. problem program runs again after again = false.

how can fix loop? think main focus @ bottom switch posted in case on looked in main part of code.

int main() { bool again = true; bool flag = false; int usernum; int count = 0; int userhold1, userhold2; userhold1 = 0; userhold2 = 0; char choice;  while ( again = true ) {     cout << "please enter positive integer: ";  // getting number test     cin >> usernum;     cout << endl;      //////////////////////////////////  finding factors      cout << "the factors of " << usernum << " are: ";       (int i=1 ; <= usernum/2 ; i++)     {         if( isafactor ( usernum , , flag) )         {           cout << << ", ";           count = count + i;  // keeping track of sum of factors         }     }     cout << "and " << usernum << endl;     count = count + usernum;      ////////////////////////////////// sum of factors      cout << "the sum of factors is: " << count << endl;        ////////////////////////////////// prime factorization      cout << "the prime factorization is: ";      getprimefac ( usernum );     cout << endl;      ////////////////////////////////// even/odd checker      cout << usernum << " ";        if ( checkeven( usernum ) == true)         cout << "even number." << endl;     else         cout << "odd number." << endl;      ////////////////////////////////// prime checker      primecheck (usernum);      ////////////////////////////////// perfect , abundant , deficient      count = 0;      ( int = 1 ; <= usernum/2 ; i++ )  // adding factors of number     {         if( isafactor ( usernum , , flag )  )             count = count + i;  // suming of factors     }      if ( count == usernum )         cout << usernum << " perfect number." << endl;     else if ( count > usernum )         cout << usernum << " abundant number." << endl;     else if ( count <usernum )         cout << usernum << " deficient number." << endl;      ////////////////////////////////// squares      squarecheck ( usernum );      ////////////////////////////////// twin primes      if ( primecheck2 ( usernum ) == true )     {         if ( primecheck2 ( usernum -2 ) == true )         {             userhold1 = ( usernum - 2 );             cout << usernum << " has twin prime: " << userhold1 << " ";               if ( primecheck2 ( usernum + 2 ) == true )             {                 userhold2 = ( usernum + 2 );                 cout << "and " << userhold2;             }         }          if ( primecheck2 ( usernum + 2 ) == true )         {             userhold1 = ( usernum + 2 );             cout << usernum << " has twin prime: " << userhold1 << " ";               if ( primecheck2 ( usernum - 2 ) == true )             {                 userhold2 = ( usernum - 2 );                 cout << "and " << userhold2;             }         }     }     cout << endl << endl;      //////////////////////////////////  end program again?       cout << "would analyze number? (y/n) :";     cin >> choice;      switch (choice)     {      case 'y': again = true;          break;      case 'n': again = false;          break;     } }  system ("pause"); } 

this line set again true , return new value of again, true.

while ( again = true ) 

try instead:

while ( again == true ) 

or better:

while ( again )