Why is order of expressions in if statement important

Question

Suppose I have an IF condition :

if (A || B) 
    ∧
    |
    |
   left
{ 
   // do something  
}

Now suppose that A

Answer 1

public class Main
{
    public static void main(String[] args) {
        System.out.println("Hello World");
        Integer a = null;
        Integer b = 3;
        Integer c = 5;

        if(a != null && a == 2){
            System.out.println("both");
        }else{
            System.out.println("false");
        }
    }
}

Hello World
false