I’m writing a piece of code that’s supposed to grow a vector to a certain size. For some reason, the boolean check within the while loop is acting strangely.

Here’s the code that I ran; the first loop doesn’t run like it’s supposed to, but the second one does. To my knowledge, they should both do the exact same thing. What’s going on?

#include <iostream>
#include <vector>
using std::cout;
using std::vector;

int main()
{
  int index = 0;
  vector<int> vec = {};

  
  //Loop 1
  while (index > (vec.size() - 2))
  {
    cout << "Visiting loop 1n";
    vec.push_back(vec.size());
  }

  bool test = (index > (vec.size() - 2));
  //I added this here because I noticed that it is initializing
  //as false, even though 0 > -2 is true. In fact,
  //when I type "p index > (vec.size() - 2)" in the debugger,
  //it says true, but when I type "p test", it says false. Why?

  vec = {};

  //Loop 2
  int compValue = vec.size() - 2;
  
  while (index > compValue)
  {
    cout << "Visiting loop 2n";
    vec.push_back(vec.size());
    compValue = vec.size() - 2;
  }

  return 0;
}