any one please explain me the below code please step by step

Question

Below code prints prime number
but i want to know why factors (variable) has 1 and 2 and then 3 and 4 value in last as its intial vale is 0 then factors++ increase its value by 1 so its final value must be 1... please explain me thank u
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#include <iostream>
using namespace std;

int main() {
cout<<"2 is prime"<<endl;/*my code skips even numbers to make it faster so i had to manualy output the only even prime number*/
int num=1;
while (num < 110){// change for more
int factors = 0;
num++;

if(num%2==0){
num++;
}
for(int i =1; i<=num; i+=2){

if (num%i==0){
factors++;
cout << "factor value " << factors << endl;
// just to show value of factors
}
}
if (factors == 2){
cout<<num<<" is prime"<<endl;
}
}
return 0;
}

Answer 1

It can be more than 1. We know a number is prime when it has 2 factors :itself and 1. So the program checks for the number of factors and it could be more than 2 . Think of 4, it can be divided by 4,by 1 and by 2 so the value is an integer which means the number of factors is 3.
Factor is 0.
Can for example 5 be divided by itself? 5/5 Yes. Factor = 1
Can 5 be divided by ? 5/1
Yes. Factor = Factor + 1 (or Factor++)
So it is 2 now.
Does the number have only 2 factors?
Yes, 5 and 1 . The number is prime.
I think thats how it works ..