Keep If Statement going until right choice?

[killertcell]

So i just wrote a program reimplemented in C++ that i originally wrote in VB.net. Only difference is that this in terminal while that VB.net project is gui. But anyways how can i keep this if statement going until the user choices the right selection? Because i entered 4 the if statement caught it was out of the valid range, the else program also caught it but the program just terminanted.

//This is the main file for the program. The program is a reimplmentation of an old vb.net project i did last year. no need for arrays in this project just using descion structures and there is also no need to use classes as i am practicing descion structures.
//(C) John Nelson 2012
#include <iostream>
#include <fstream>
using namespace std;

int main(){
  //create a writer to save to a text file
 ofstream writer; 
 writer.open("rental.text");
 
 
 //this choice will be used for the descion structure for the user to input what car he wants.
 int choice = 0;
 double days;
 //these constant variables are the fixed price cost it is to rent these viechials
 const double gp40mc = 180;
 const double F40PH = 150;
 const double Spaceship = 1080;
 double total;
 
 cout << "Hello What Veichal do you want to rent enter a number 1,2,3 and make a selection." << endl << "1.GP40MC." << endl << "2.F40ph:." << endl << "3.Spaceship:" << endl;
 
 cin >> choice;
 if (choice >= 1 && choice <= 3);
   else{
     cout << "You did not enter the right choice please enter it again";
     cout << "Hello What car do you want to rent enter a number 1,2,3 and make a selection." << endl << "1.GP40MC." << endl << "2.F40ph:." << endl << "3.Spaceship:" << endl;
     cin >> choice;}
     
     if (choice == 1){
       cout << "How many days are you going to be renting the GP40MC for? There is no limit on the amount of days but the cost to rent it is $180 a day gas is included as well!";
       cin >> days;
       total = days * gp40mc;
       cout << "The total cost of your rental is $" << total << endl << "Thank you for shopping here your receipt is also in the text file good day sir!" << endl;
       writer << "Your Receipt: " <<endl << "Vehcial Rental: GP40MC     Days Rental:" << days << "Final Cost:" << total << endl;}
       
      else if (choice == 2){
	 cout << "How many days are you going to be renting the F40PH for? There is no limit on the amount of days but the cost to rent it is $150 a day gas is included as well!";
       cin >> days;
       total = days * F40PH;
       cout << "The total cost of your rental is $" << total << endl << "Thank you for shopping here your receipt is also in the text file good day sir!" << endl;
       writer << "Your Receipt: " <<endl << "Vehcial Rental: F40PH     Days Rental:" << days << "Final Cost:" << total << endl;}
       
       else if (choice == 3){
	 cout << "How many days are you going to be renting the Spaceship for? There is no limit on the amount of days but the cost to rent it is $1080 a day gas is included as well!";
       cin >> days;
       total = days * Spaceship;
       cout << "The total cost of your rental is $" << total << endl << "Thank you for shopping here your receipt is also in the text file good day sir!" << endl;
       writer << "Your Receipt: " <<endl << "Vehcial Rental: Spaceship     Days Rental:" << days << "Final Cost:" << total << endl;
     };
  
}

[killertcell]

i did not know it would be that long on one line.. I used kate so it wrapped automatically

[hanst99]

You got some weird spacing. For selections like this, a switch statement would probably be better (even if you want to use "if", you are doing it in a rather strange fashion).

Example:

switch(value) {
case 1:
   do_something();
   break;
case 2:
   do_something_else();
   break;
default:
   none_of_the_above();
}

You can only "switch" on integers though (like char, short, int, long...)

As for the other thing: Just wrap the whole thing in a loop.

[killertcell]

thanks i completely forgot about the switch i will rewrite it with that.