#include <iostream>
using namespace std;
int main() {
int x=5;
int p=5;
int y=x+--x;
int q=p+++p;
cout<<y<<" "<<q;
return 0;
}
output: 8 11
expected : 8 12 or 9 11
'+' operator and prefix/postfix operator have the same precedence. Which means that none of them come first or come last when processing them.
Its like 3+4+5. You can add 4 and 5 first. Or you can add 3 and 4 first.
In this case, we call this "Undefined Behaviour". Where the compiler may give different possible results.
