What is wrong with my c++ code?

#include %26lt;iostream.h%26gt;





int main() {


int num, num2,a,b;


do{


cout %26lt;%26lt; "Enter a value in the range of 1 to 100: ";


cin %26gt;%26gt; num;


if(num %26lt; 1 || num %26gt; 100)


cout %26lt;%26lt; "Out of range; Please try again... " %26lt;%26lt; endl


%26lt;%26lt; endl;


}while (num %26lt; 1 || num %26gt; 100);





int counter = 0;


for (a = 0; a %26lt;= num; a++){


}


for (b = 1; b %26lt; a; b++){


if (a % b == 0)





counter++;





if (counter == 1)





cout%26lt;%26lt; "The prime numbers are " %26lt;%26lt; a %26lt;%26lt; " ";


}


return 0;


}





Enter a value from 1 to 100: -5


Out of range; Please try again...





Enter a value from 1 to 100: 200


Out of range; Please try again...





Enter a value from 1 to 100: 101


Out of range; Please try again...





Enter a value from 1 to 100: 45





The prime numbers are:


1 2 3 5 7 11 13 17 19 23 29 31 37 41 43





This is what the output supposed to look like, but when I ran my code, the prime number output does not come out right. can anyone help me fix the problem?

What is wrong with my c++ code?
Here is a cleaner version of your code:





#include %26lt;iostream.h%26gt;





// The following functions works on positive integers greater


// than zero only





bool isPrime(int number);





int main()


{


int num= 0;





do


{


cout %26lt;%26lt; "Enter a value in the range of 1 to 100: ";


cin %26gt;%26gt; num;





if(num %26lt; 1 || num %26gt; 100)


cout %26lt;%26lt; "Out of range; Please try again... " %26lt;%26lt; endl


%26lt;%26lt; endl;





}while(num%26lt; 1 || num %26gt; 100);





cout%26lt;%26lt; "The prime numbers are: " %26lt;%26lt; endl;


for(int i = 1; i %26lt; num; i++)


{


if(isPrime(i))


cout %26lt;%26lt; i %26lt;%26lt; " ";


}





cout %26lt;%26lt; endl;





return 0;


}





bool isPrime(int number)


{


for(int i = 2; i %26lt; number - 1; i++)


{


if((number % i) == 0)


return false;


}


return true;


}
Reply:heres the problem with your code. you wrote:





int counter = 0;


for (a = 0; a %26lt;= num; a++){


}


for (b = 1; b %26lt; a; b++){


if (a % b == 0)





counter++;





if (counter == 1)





cout%26lt;%26lt; "The prime numbers are " %26lt;%26lt; a %26lt;%26lt; " ";


}








your first "for" loop does nothing because there is nothing between the brackets.


the loop is:


for (a = 0; a %26lt;= num; a++){


}








i think what you wanted is this:


for (a = 0; a %26lt;= num; a++)


__{


__for (b = 1; b %26lt; a; b++)


____{


____if (a % b == 0)


______counter++;


____if (counter == 1)


______cout%26lt;%26lt; "The prime numbers are " %26lt;%26lt; a %26lt;%26lt; " ";


____}


__}
Reply:First you haven't initialised your variable so it might already have a number value within the range. Set it to zero before you start. num=0;





It also looks like your program will only run through the counter and then output prime numbers if the counter = 1. You need to output your numbers from within a loop so that they are output each time you reach one.
Reply:oh





big mistake








A %26amp; B is missing before C








bye





good night

bloom