### Re start a program Practicing my if/else functions with a simple number program that asks the user to input and carry out functions to a chosen number. If the user inputs the wrong answer or an invalid number I would like the code to be able to be restarted. Is there any way of doing this?

 ``123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263`` `````` #include using namespace std; void correct() //Function to display text if correct answer inputted { cout << "Correct\n" << endl; } void incorrect() { cout << "Incorrect, press r to start again" << endl; //Function to display text if incorrect answer inputted //some code to make program restart if r is pressed } int main() { int x; cout << "Enter am integer between 1 and 10 (inclusive)" << endl; cin >> x; if (x > 0 && x < 11) { cout << "Thank you\n" << endl; } else { cout << "Number invalid, press r to start again\n" << endl; return 0; } cout << "Please double your number" << endl; int y; cin >> y; if (y == x*2) { correct(); } else { incorrect(); return 0; //Ends program } cout << "Please add 2 to your number" << endl; int z; cin >> z; if (z == y + 2) { correct(); } else { incorrect(); return 0; //Ends program } return 0; } `````` The whole main function?

You could do something like

 ``1234567891011121314`` ``````int main() { while (true) // or whatever other condition, if you want to limit it) { //stuff you already have ... else { incorrect(); //instead of returning... continue; //makes it start back at the top of the while loop } } }``````

Last edited on If I do that though it says

 `` `` ``error: 'else' without a previous 'if'`` And would something like this work in the while loop?

 `` `` ``while (y == x*2 && z == y + 2)`` The ellipsis was supposed to mean the rest of the code.

As in, wrap everything you currently have in main() around a while loop, but change the returns to continues.

 ``12345678910`` `````` if (y == x*2) { correct(); } else { incorrect(); continue; } //do this for the other places you want to "restart" instead of return as well ``````

Edit: If you want a condition in your while loop, it would be a condition that, if evaluated to false, would make the program end. You could have a "num_tries" that gets incremented, and it num_tries goes above 10 or something, it ends the loop.

Just to clarify...
 ``1234567891011121314151617181920212223242526272829303132333435363738394041424344454647`` ``````int main() { while (true) { int x; cout << "Enter am integer between 1 and 10 (inclusive)" << endl; cin >> x; if (x > 0 && x < 11) cout << "Thank you\n" << endl; else { cout << "Number invalid, press r to start again\n" << endl; continue; //restarts to beginning of while loop } cout << "Please double your number" << endl; int y; cin >> y; if (y == x*2) { correct(); } else { incorrect(); continue; //restarts to beginning of while loop } cout << "Please add 2 to your number" << endl; int z; cin >> z; if (z == y + 2) { correct(); } else { incorrect(); continue; //restarts to beginning of while loop } //If this point is reached, it means the person followed the directions correctly. break; //ends loop, allows program to return and exit. } return 0; }``````
Last edited on Right that all works now (I included a break; after the last if to end the program if the user gets to the last function correctly), thanks for the help. Just out of interest (not that you'd need/want to do this but) would it be possible to make the program restart if the user inputs a character?
Last edited on You could have something like

 ``12345678910111213`` ``````if (whatever condition) correct(); else { incorrect(); cout << "Enter y to restart: "; char c; cin >> c; if (c == 'y') continue; else return 1; }``````

There's probably a better way to structure the program but it works.
Last edited on Ahh thank you very much. In what way could it be better? I'm a total beginner so if you could suggest a general solution kind of thing I could work through to help me improve that would be fab, if not maybe some specific pointers? you should use do while loop here.
Here's the fix code
 ``123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354`` ``````#include using namespace std; int z; void correct() //Function to display text if correct answer inputted { cout << "Correct\n" << endl; } void incorrect() { cout << "Incorrect, press r to start again" << endl; //Function to display text if incorrect answer inputted //some code to make program restart if r is pressed } int main() { int x; do{ cout << "Enter am integer between 1 and 10 (inclusive)" << endl; cin >> x; } while(x<1 || x>10); // here's your problem i changed it into do while loop if the input // is wrong the program will be restarted cout << "Please double your number" << endl; int y; cin >> y; if (y == x*2) { correct(); } else { incorrect(); return 0; //Ends program } cout << "Please add 2 to your number" << endl; int z; cin >> z; if (z == y + 2) { correct(); } else { incorrect(); return 0; //Ends program } return 0; }``````
Last edited on
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