Consider

#include <iostream>
int main()
{
    int i = 0;    
    while (i < 10)
    i  ;
    std::cout << i << endl;
}

I just wanted to know, why does this print out 10? if it is i < 10, shouldn't it be 9 that is printed? I appreciate any help

CodePudding user response：

Because when i is 9, (i < 10) is true, so the while body runs, which increments i by 1 thereby setting it to 10. Sure, on that last iteration of the while body, i is an expression equal to 9, but with the side-effect of increasing i.

CodePudding user response：

Regardless of what happens inside the loop,

do this as long as i is less than 10

is the same as

do this until i is greater than or equal to 10

So the value of i after the loop must be (at least) 10, since that's when it stops.