Finding Prime number without any loop

**RanaFaheemAg** · 28th October 2013, 06:46 PM

#include<iostream.h> //Created by:RanaFaheemA.G Oct/28/2013
#include<conio.h>
void main(){
clrscr();
long user;
repeat:
cout<<"\n\n\tType an integer to know whether it is prime num or not\t";
cin>>user;
// 2,3,5,7 are prime numbers
if(user==2 || user==3 || user==5 || user==7 )
cout<<"\n\t"<<user <<"\tis a prime number";
// these are not prime numbers
else if(user%2==0 || user%3==0 || user%5==0 || user%7==0 || user%9==0)
cout<<"\n\t"<<user <<"\tis not prime number";
//these are prime numbers
else
cout<<"\n\t"<<user <<"\tis a prime number";

//continuing program
char choice;
cout<<"\n\n\tContinue? (Y/N)\t";
cin>>choice;
if(choice=='Y' || choice=='y')goto repeat;
else
cout<<"\n\tPress any key to close...\n\n\n\n\n";
getch();
}