Unsigned and signed comparison

Question

Here is very simple code,

#include 
using namespace std;
int main() {
    unsigned int u=10;
    int i;
    int count=0;
    for (i=-1;i<=         


        

Answer 1

This is because i is promoted to an unsigned value before comparison. This will set it to the value of UINT_MAX, which on a 32 bit machine equals to 4294967295. So your loop is essentially the same as:

// will never run
for (i = 4294967295; i <= u; i++) {
    count++;
}