I want to solve this expression

// Java program

class HelloWorld {
    public static void main(String[] args) {
        int i = 5;
        i += i++ + i-- + i--;
        System.out.println(i);
    }
}

The confusion arises from the order of operations. The output is 21 because the post-increment and post-decrement operations are evaluated after the current value of ‘i’ is used. Thus, ‘i’ is added to itself before the increments and decrements occur. This is why the result differs from the expected 19.