c++ - My program will loop regardless of whatever char I enter -


i have been working on very basic calculation program in c++. calculates square root of number, , squares if user wants. have far (i know it's rubbish code, i'm beginner experimenting see how works. suggestions appreciated though):

#include <iostream> #include <stdlib.h> #include <math.h>  using namespace std;  int number;         // global variables used in void functions main. int squarednumber; double sqrtresult; char input; char useagain;  void squarenum();       // prototypes void functions void sqrtnum(); void useagainquery();  int main() { retry:                      // establishing somewhere send user if input invalid.     system("cls");     cout << "square calcualtions" << endl;     cout << "******************" << endl;     cout << endl;     cout << "do want square number or find square root of number?" << endl;     cout << "please select 1 or 2 respectively." << endl;     cout << endl;     cin >> input;     if (input == '1')     {         cout << "please press enter continue." << endl;         cin.ignore().get();         squarenum();                // if input 1, run void square number.     }     else if (input == '2')     {         cout << "please press enter continue." << endl;         cin.ignore().get();         sqrtnum();                  // if input 2, run void sqrt number.     }     else if (input != '1' || '2')     {         system("cls");         cout << "square calcualtions" << endl;         cout << "******************" << endl;         cout << endl;         cout << "your selection invalid, please enter 1 or 2." << endl;         cin.ignore().get();         goto retry;             // if input isn't either 1 or 2, send start of program.     }     return 0; }  void squarenum()  // function square inputted number. {     system("cls");     cout << "square calcualtions" << endl;     cout << "******************" << endl;     cout << endl;     cout << "enter number want square." << endl;     cin >> number;     cout << "you have chosen: " << number << endl;     cout << "press enter calculate." << endl;     cin.ignore().get();     system("cls");     squarednumber = number * number;        // simple maths find square number     cout << "you have squared " << number << "." << endl;     cout << "the result " << squarednumber << "." << endl;     cout << "press enter continue." << endl;     cin.get();     useagainquery();     return; }  void sqrtnum() {     system("cls");     cout << "square calcualtions" << endl;     cout << "******************" << endl;     cout << endl;     cout << "enter number square root of." << endl;     cin >> number;     cout << "you have chosen: " << number << "." << endl;     cout << "press enter calculate." << endl;     cin.ignore().get();     system("cls");     sqrtresult = sqrt(number);     cout << "you have found square root of " << number << "." << endl;     cout << "the result was: " << sqrtresult << "." << endl;     cout << "press enter continue." << endl;     cin.get();     useagainquery();     return; }  void useagainquery() {     system("cls");     cout << "square calcualtions" << endl;     cout << "******************" << endl;     cout << endl;     cout << "would make calculation?" << endl;     cout << "y yes , n no." << endl;     cout << endl;     cin >> useagain;     if (useagain == 'y' || 'y')     {     retry2:                     // establishing somewhere send user if input invalid.         system("cls");         cout << "square calcualtions" << endl;         cout << "******************" << endl;         cout << endl;         cout << "do want square number or find square root of number?" << endl;         cout << "please select 1 or 2 respectively." << endl;         cout << endl;         cin >> input;         if (input == '1')         {             cout << "please press enter continue." << endl;             cin.ignore().get();             squarenum();                // if input 1, run void square number.         }         else if (input == '2')         {             cout << "please press enter continue." << endl;             cin.ignore().get();             sqrtnum();                  // if input 2, run void sqrt number.         }         else if (input != '1' || '2')         {             system("cls");             cout << "square calcualtions" << endl;             cout << "******************" << endl;             cout << endl;             cout << "your selection invalid, please enter 1 or 2." << endl;             cin.ignore().get();             goto retry2;         }     }     else if (useagain != 'y' || 'y')         return;     return; }

so yeah, when go through , asks "would play again", goes through on , over. doesn't matter key press loops. appreciated!

change condition here:

    if (useagain == 'y' || 'y')

to

    if (useagain == 'y' || useagain=='y')

also, change this:

 else if (useagain != 'y' || 'y') {     return; }

to this:

else if (useagain != 'y' && useagain!='y') {     return; }

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