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I was messing around with some C code for my compilers class, and ran into some Inconsistent/unexpected behavior, as shown below.
This code:
#include <stdio.h>
int main()
{
int x, y;
x = 2;
y = x + (++x) + x;
printf("%d\n", y);
x = 2;
y = x + x + (++x) + x;
printf("%d\n", y);
return 0;
}
returns:
9
10
In the first assignment of y, the (++x) appears to be executed prior to the evaluation of the first instance of x, while in the second example, (++x) is executed in what appears to be the correct order (if I were calculating it by hand).
What is the cause of the the difference of the order of execution?
