// j = i++

class Demo{
    public static void main(String[] args)
    {
        int i = 3; 
        int j = i++;

        System.out.println("j = " + j + " i = " + i);
        // j = 3 i = 4
    }
}

// i = i++
class Demo{
    public static void main(String[] args)
    {
        int i = 3;
        i = i++;

        System.out.println("i = " + i);
        // i = 3
    }
}