int fibonacci(int n) {

    if (n <= 0) return 0;

    if (n == 1) return 1;

    int a = 0, b = 1, temp;
    for (int i = 2; i <= n; i++) {
        temp = a + b;
        a = b;
        b = temp;
    }
    return b;

}

...if only the return type was "Crow" then you could .eat() that...

That will not compile with javac, as it is not a method of a class.

That code will it just needs to be in the proper context. No the same file will not compile, even if only because javac needs files to end with .java .

Java has "unnamed classes" now which makes this work.