can someone explain whats going on

here is a full working program to check a number for primeness

i need an expert who can explain it for me particularly the section //print results

what is if(is_prime) mean.

#include <iostream>

#include <cmath>

using namespace std;

int main() {

int n; // Number to test for prime-ness

int i; // Loop counter

int is_prime = true; // Boolean flag...

// Assume true for now.

// Get a number from the keyboard.

cout << "Enter a number and press ENTER: ";

cin >> n;

// Test for prime by checking for divisibility

// by all whole numbers from 2 to sqrt(n).

i = 2;

while (i <= sqrt(n)) { // While i is <= sqrt(n),

if (n % i == 0) // If i divides n,

is_prime = false; // n is not prime.

i++; // Add 1 to i.

}

// Print results

if (is_prime)

cout << "Number is prime." << endl;

else

cout << "Number is not prime." << endl;

system("PAUSE");

return 0;

}

Re: can someone explain whats going on

Quote:

Originally Posted by

**TalkTime**
here is a full working program to check a number for primeness

Next time, please use code tags when posting code. Your code is almost unreadable without using them.

Quote:

i need an expert who can explain it for me particularly the section //print results

what is if(is_prime) mean.

What part of that statement is confusing you? The if()? The is_prime? The is_prime is either **true** or **false**, and the if() statement executes if it is **true**.

Regards,

Paul McKenzie