Why is x == (x = y) not the same as (x = y) == x?

Question

Consider the following example:

class Quirky {
    public static void main(String[] args) {
        int x = 1;
        int y = 3;

        System.out.println(x =         


        

Answer 1

== is a comparison equality operator and it works from left to right.

x == (x = y);

here the old assigned value of x is compared with new assign value of x, (1==3)//false

(x = y) == x;

Whereas, here new assign value of x is compared with the new holding value of x assigned to it just before comparison, (3==3)//true

Now consider this

    System.out.println((8 + (5 * 6)) * 9);
    System.out.println(8 + (5 * 6) * 9);
    System.out.println((8 + 5) * 6 * 9);
    System.out.println((8 + (5) * 6) * 9);
    System.out.println(8 + 5 * 6 * 9);

Output:

342

278

702

342

278

Thus, Parentheses plays its major role in arithmetic expressions only not in comparison expressions.