Boolean expressions optimizations in Java

Question

Consider the following method in Java:

public static boolean expensiveComputation() {
    for (int i = 0; i < Integer.MAX_VALUE; ++i);
    return false;
}         


        

Answer 1

The compiler will optimize this if you run the code often enough, probably by inlining the method and simplifying the resulting boolean expression (but most likely not by reordering the arguments of &&).

You can benchmark this by timing a loop of say a million iterations of this code repeatedly. The first iteration or two are much slower than the following.